What are the key sources, functions, and recommended daily intakes of essential vitamins. How do nutrient deficiencies occur and what are the associated health consequences.

Key Sources of Essential Vitamins

Essential vitamins can be obtained from a variety of food sources. Some of the major dietary sources include:

• Liver, kidneys, meats, eggs, milk, fish, dried yeast, sweet potatoes, seeds, and nuts for Vitamin B12
• Raw green leafy vegetables, asparagus, broccoli, fruits (especially citrus), liver, other organ meats, dried yeast, and enriched breads, pastas, and cereals for Folate
• Dried yeast, liver, red meat, poultry, fish, legumes, and whole-grain or enriched cereal products and bread for Niacin
• Liver, beef, egg yolks, yeast, potatoes, broccoli, and whole grains for Pantothenic Acid
• Milk, cheese, liver, meat, fish, eggs, and enriched cereals for Riboflavin
• Dried yeast, whole grains, meat (especially pork and liver), enriched cereals, nuts, legumes, and potatoes for Thiamin
• Fish liver oils, liver, egg yolks, butter, cream, and fortified milk as well as dark green, yellow, and orange vegetables and yellow and orange fruits for Vitamin A
• Dried yeast, liver, other organ meats, whole-grain cereals, fish, and legumes for Vitamin B6

Functions of Essential Vitamins

Each essential vitamin plays a critical role in various bodily functions:

• Vitamin B12 is required for the formation of red blood cells, DNA and RNA synthesis, and normal nervous system development
• Folate is necessary for the metabolism of carbohydrates, fats, and many other substances, as well as for the normal functioning of cells
• Niacin is involved in the metabolism of carbohydrates, fats, and many other substances and for the normal functioning of cells
• Pantothenic Acid is required for the metabolism of carbohydrates and fats
• Riboflavin is needed for the metabolism of carbohydrates and proteins and for healthy mucous membranes
• Thiamin is essential for the metabolism of carbohydrates, proteins, and fats and for normal nerve and heart function
• Vitamin A is required to form light-sensitive nerve cells in the retina, helping maintain night vision, and it also helps maintain the health of the skin, cornea, and lining of the lungs, intestine, and urinary tract
• Vitamin B6 is involved in the metabolism of carbohydrates, proteins, and fats and for normal nerve and heart function

Recommended Daily Intakes of Essential Vitamins

The recommended daily intakes for essential vitamins vary based on age, gender, and life stage:

• Vitamin B12: 30 micrograms (no RDA established), 35 micrograms for breastfeeding women
• Folate: 600 micrograms for pregnant women, 500 micrograms for breastfeeding women
• Niacin: 18 milligrams for pregnant women, 17 milligrams for breastfeeding women
• Pantothenic Acid: 5 milligrams (no RDA established), 6 milligrams for pregnant women, 7 milligrams for breastfeeding women
• Riboflavin: 1.4 milligrams for pregnant women, 1.6 milligrams for breastfeeding women
• Thiamin: 1.4 milligrams for pregnant or breastfeeding women
• Vitamin A: 770 micrograms for pregnant women, 1,300 micrograms for breastfeeding women
• Vitamin B6: 1.9 milligrams for pregnant women, 2.0 milligrams for breastfeeding women

Nutrient Deficiencies and Health Consequences

Nutrient deficiencies can occur due to inadequate dietary intake, poor absorption, or increased requirements during certain life stages or health conditions. The potential health consequences of deficiencies include:

Vitamin B12 Deficiency

Vitamin B12 deficiency can lead to anemia, neurological problems, and developmental issues in fetuses and infants. It is most common in individuals with pernicious anemia, vegans, or those with malabsorption disorders.

Folate Deficiency

Folate deficiency can result in megaloblastic anemia, neural tube defects in developing fetuses, and increased risk of cardiovascular disease. It is particularly important for pregnant women to ensure adequate folate intake.

Niacin Deficiency

Niacin deficiency, also known as pellagra, can cause skin rashes, diarrhea, dementia, and even death if left untreated. It is most common in populations with limited access to niacin-rich foods.

Pantothenic Acid Deficiency

Pantothenic Acid deficiency is rare, but it can lead to fatigue, irritability, and gastrointestinal issues. It is more likely to occur in individuals with malabsorption disorders or those on restrictive diets.

Preventing Nutrient Deficiencies

To prevent nutrient deficiencies, it is important to consume a varied, nutrient-dense diet that includes a wide range of foods rich in essential vitamins. Supplementation may be necessary for certain individuals, such as pregnant women, the elderly, or those with underlying health conditions. Regular check-ups and monitoring of nutrient levels can also help identify and address any deficiencies before they lead to more serious health problems.

Conclusion

In summary, essential vitamins play a crucial role in maintaining overall health and well-being. By understanding the key sources, functions, and recommended intakes of these vitamins, individuals can take proactive steps to ensure they are meeting their nutritional needs and preventing potential deficiencies. Proper nutrition, along with regular medical care, is the foundation for a healthy lifestyle.

Overview of Vitamins – Disorders of Nutrition

Fat-soluble vitamins: Types, function, and sources

We include products we think are useful for our readers. If you buy through links on this page, we may earn a small commission. Here’s our process.

Fat-soluble vitamins are vitamins A, D, E, and K. They are present in foods containing fats. The body absorbs these vitamins as it does dietary fats. They do not dissolve in water.

Vitamins help the body function effectively. There are two types: water-soluble and fat-soluble vitamins. The water-soluble vitamins are vitamins B and C.

Most vitamins come from food, but sunshine contributes to vitamin D. Some people need or choose to take supplements that provide extra vitamins.

The body absorbs fat-soluble vitamins best when a person eats them with higher-fat foods.

This article looks at the types, functions, and sources of fat-soluble vitamins, and what can happen if a person has too much or too little.

Vitamin A helps maintain healthy vision. Without vitamin A, a person could experience vision problems and possibly vision loss.

Types

Vitamin A is not a single vitamin but a collection of compounds known as retinoids. Retinoids occur naturally in the human body, and they are present in some dietary sources.

Some foods provide retinols, which the body can use directly as vitamin A. Others provide provitamin A, compounds that the body converts into vitamin A.

Function

Vitamin A supports several functions throughout the body, including:

Learn more here about why we need vitamin A.

Dietary sources

People can obtain vitamin A through dietary sources.

Animal sources provide preformed vitamin A, or retinols. This type is ready for the body to use.

Plant sources provide carotenoids, such as beta-carotene, which is a powerful antioxidant. The body can convert these into vitamin A.

For this reason, lists of ingredients often show vitamin A content as “vitamin A RAE.” RAE means “retinol activity equivalents.”

Animal sources of vitamin A include:

• fish liver oil
• beef liver
• cheese, milk, and other dairy products
• Sources of beta carotene include:
• sweet potato
• kale, spinach, and other green, leafy vegetables
• carrots
• cantaloupe
• black-eyed peas
• fortified breakfast cereals

Find out more here about dietary sources of vitamin A.

Recommended intake

Nutritionists measure some vitamins in two ways:

• micrograms (mcg) RAE
• international units (IU)

Food packages usually show the amounts in IU. A diet that contains 900 mcg RAE of vitamin A, which is the recommended intake for males over 14 years of age, would provide around 3,000–36,000 IU of vitamin A, according to the Office of Dietary Supplements (ODS).

Anyone who has concerns about their vitamin A intake should seek advice from a health professional, who will help them understand these measures.

The recommended intake of vitamin A varies by age and sex.

The 2015–2020 Dietary Guidelines for Americans recommend consuming the following amounts each day. Amounts are in mcg RAE.

Deficiency

Vitamin A deficiency is rare in the United States, but it can affect a person who:

A long-term deficiency can lead to a loss of night vision and possibly a total loss of vision.

Overdose

Too much vitamin A can be toxic.

It can affect:

• people who take vitamin A supplements
• those with a high intake of fish liver oil
• people who take medications that contain retinoids, such as acitretin (Soriatane), a treatment for psoriasis

During pregnancy, high levels of vitamin A can harm a growing fetus.

Symptoms of an overdose include:

In severe cases, coma and death can result.

Vitamin A supplements are available for purchase online. However, people should speak to a doctor before taking these or other supplements.

The time a person takes a vitamin can affect its impact. Find out more here about when to take different vitamins.

People obtain vitamin D:

• naturally through exposure to sunlight or in the diet
• through fortified foods
• as supplements

The body obtains the compounds it needs to make vitamin D from food. It also produces vitamin D when ultraviolet (UV) light meets the skin.

Types

Vitamin D is not a single substance but a group of compounds collectively known as calciferol.

The body absorbs calciferol into the bloodstream and then converts it to calcitriol.

Two types occur naturally:

• vitamin D-3, found in animal fats
• vitamin D-2, found in plants, such as mushrooms

Function

Vitamin D has two main roles in the body:

• It maintains bone health.
• It supports the immune system.

Find out more about the health benefits of vitamin D.

Dietary sources

A person can obtain some vitamin D from the sun, but most people will also need to use other sources, too. The main alternative is food.

Dietary sources include:

• oily fish and fish oils
• fortified dairy products, plant-based milks, and cereals
• beef liver
• eggs

How can you get more vitamin D from the sun? Click here to find out.

Recommended intake

Experts measure vitamin D in international units (IU).

Current guidelines recommend that people of all ages intake of 600 IU of vitamin D daily. This is hard to measure, however, as it is not easy for a person to know how much vitamin D they obtain from sunlight.

Deficiency

A vitamin D deficiency can affect:

• older adults and children who do not spend much time out of doors
• people with darker skin
• some people with chronic health conditions
• those who live far from the Equator, where winter days are short
• those with obesity

The main effects of vitamin D deficiency include:

• osteomalacia, when bones become soft
• rickets, when a child’s bones do not develop as they should
• increased risk of infection and autoimmunity

Learn more about vitamin D deficiency.

Overdose

It is rare for a person to have too much vitamin D, but using supplements could trigger this.

Having too much vitamin D could lead to high levels of calcium in the blood.

This can lead to:

• nausea
• headaches
• low appetite and weight loss
• a buildup of calcium in tissues and blood vessels
• heart or kidney damage
• high blood pressure

Vitamin D supplements are available for purchase in pharmacies and online. A person should speak to their doctor before using these supplements, however.

Vitamin E is an antioxidant that can help the body destroy free radicals. Free radicals are unstable atoms that can cause oxidative stress. Oxidative stress can lead to cell damage, and this can result in cancer and other diseases. Vitamin E may help protect the body from a range of health issues.

Types

There are eight forms of vitamin E, but only alpha-tocopherol meets humans’ needs, according to the ODS.

Function

Some reasons why the body needs vitamin E are:

• as an antioxidant
• to boost the immune system
• to dilate blood vessels and help prevent clotting

Dietary sources

Good sources of vitamin E include:

• wheat germ oil
• sunflower seeds and oil
• almonds, hazelnuts, and peanuts
• spinach and broccoli
• kiwi fruit and mango

Which foods are good sources of vitamin E? Find out here.

Recommended intake

Current guidelines recommend people consume the following amounts of vitamin E. Experts measure vitamin E intake in milligrams (mg) AT, but packaging currently uses international units (IU).

The ODS note that, during breastfeeding, a female should consume 19 mg (28.4 IU) each day.

Deficiency

Vitamin E deficiency is rare, but it can affect people with Crohn’s disease or cystic fibrosis. These conditions affect the liver’s ability to absorb vitamin E.

A deficiency can result in:

• nerve and muscle damage that affects movement and coordination
• vision problems
• a weakened immune system

As vitamin E is an antioxidant, a long-term deficiency could increase the overall risk of various diseases.

Click here to find out how to recognize a vitamin E deficiency.

Overdose

Obtaining vitamin E through natural sources is unlikely to lead to an overdose, although supplement use can increase this risk.

People who use blood-thinning medication, such as warfarin (Coumadin) should ask their doctor before taking vitamin E supplements, as these may interfere with blood clotting.

Vitamin E supplements are available for purchase in pharmacies and online.

Vitamin K helps the body form blood clots. Blood clotting is essential to prevent excessive bleeding.

Types

There are several types of vitamin K.

The two most common groups are:

• Vitamin K-1 (phylloquinone), present in green, leafy vegetables and some other plant sources
• Vitamin K-2 (menaquinones), present in animal sources and fermented foods

There are also synthetic forms and other forms that the body makes.

Function

Apart from blood clotting, vitamin K may also:

• lower the risk of heart disease
• enhance bone health
• reduce the buildup of calcium in the blood

Learn more here about why we need vitamin K and where to get it.

Dietary sources

Food sources of vitamin K-1 and K-2 include:

• kale
• liver
• spinach
• parsley
• butter
• egg yolks

Learn about 40 foods that provide vitamin K.

Recommended intake

Experts do not have enough evidence to recommend a specific intake of vitamin K suitable to meet the needs of 97-98% of healthy individuals.

Instead, they recommend an adequate intake (AI), an amount assumed to provide nutritional adequacy, as follows:

Deficiency

The body is not able to store as much vitamin K as it does vitamin A or D. This means a person needs a regular intake of vitamin K, and there is a higher chance of a deficiency.

A vitamin K deficiency may result in:

• excess bleeding
• lower bone density, in the long term

Learn more about a vitamin K deficiency here.

Overdose

Taking high quantities of vitamin K does not appear to lead to adverse effects. However, it can interfere with the use of blood-thinning medications, such as warfarin (Coumadin).

Vitamin K supplements are available for purchase in pharmacies and online. However, people should speak to a doctor before using them, especially if they use blood thinners or have a condition that affects blood clotting.

Fat-soluble vitamins are essential for overall health. Most people can obtain enough of each vitamin from a varied and healthful diet. Anyone who has concerns about their vitamin intake should speak to a doctor.

In some cases, a doctor may recommend taking supplements.

Fat-soluble vitamins: Types, function, and sources

We include products we think are useful for our readers. If you buy through links on this page, we may earn a small commission. Here’s our process.

Fat-soluble vitamins are vitamins A, D, E, and K. They are present in foods containing fats. The body absorbs these vitamins as it does dietary fats. They do not dissolve in water.

Vitamins help the body function effectively. There are two types: water-soluble and fat-soluble vitamins. The water-soluble vitamins are vitamins B and C.

Most vitamins come from food, but sunshine contributes to vitamin D. Some people need or choose to take supplements that provide extra vitamins.

The body absorbs fat-soluble vitamins best when a person eats them with higher-fat foods.

This article looks at the types, functions, and sources of fat-soluble vitamins, and what can happen if a person has too much or too little.

Vitamin A helps maintain healthy vision. Without vitamin A, a person could experience vision problems and possibly vision loss.

Types

Vitamin A is not a single vitamin but a collection of compounds known as retinoids. Retinoids occur naturally in the human body, and they are present in some dietary sources.

Some foods provide retinols, which the body can use directly as vitamin A. Others provide provitamin A, compounds that the body converts into vitamin A.

Function

Vitamin A supports several functions throughout the body, including:

Learn more here about why we need vitamin A.

Dietary sources

People can obtain vitamin A through dietary sources.

Animal sources provide preformed vitamin A, or retinols. This type is ready for the body to use.

Plant sources provide carotenoids, such as beta-carotene, which is a powerful antioxidant. The body can convert these into vitamin A.

For this reason, lists of ingredients often show vitamin A content as “vitamin A RAE.” RAE means “retinol activity equivalents.”

Animal sources of vitamin A include:

• fish liver oil
• beef liver
• cheese, milk, and other dairy products
• Sources of beta carotene include:
• sweet potato
• kale, spinach, and other green, leafy vegetables
• carrots
• cantaloupe
• black-eyed peas
• fortified breakfast cereals

Find out more here about dietary sources of vitamin A.

Recommended intake

Nutritionists measure some vitamins in two ways:

• micrograms (mcg) RAE
• international units (IU)

Food packages usually show the amounts in IU. A diet that contains 900 mcg RAE of vitamin A, which is the recommended intake for males over 14 years of age, would provide around 3,000–36,000 IU of vitamin A, according to the Office of Dietary Supplements (ODS).

Anyone who has concerns about their vitamin A intake should seek advice from a health professional, who will help them understand these measures.

The recommended intake of vitamin A varies by age and sex.

The 2015–2020 Dietary Guidelines for Americans recommend consuming the following amounts each day. Amounts are in mcg RAE.

Deficiency

Vitamin A deficiency is rare in the United States, but it can affect a person who:

A long-term deficiency can lead to a loss of night vision and possibly a total loss of vision.

Overdose

Too much vitamin A can be toxic.

It can affect:

• people who take vitamin A supplements
• those with a high intake of fish liver oil
• people who take medications that contain retinoids, such as acitretin (Soriatane), a treatment for psoriasis

During pregnancy, high levels of vitamin A can harm a growing fetus.

Symptoms of an overdose include:

In severe cases, coma and death can result.

Vitamin A supplements are available for purchase online. However, people should speak to a doctor before taking these or other supplements.

The time a person takes a vitamin can affect its impact. Find out more here about when to take different vitamins.

People obtain vitamin D:

• naturally through exposure to sunlight or in the diet
• through fortified foods
• as supplements

The body obtains the compounds it needs to make vitamin D from food. It also produces vitamin D when ultraviolet (UV) light meets the skin.

Types

Vitamin D is not a single substance but a group of compounds collectively known as calciferol.

The body absorbs calciferol into the bloodstream and then converts it to calcitriol.

Two types occur naturally:

• vitamin D-3, found in animal fats
• vitamin D-2, found in plants, such as mushrooms

Function

Vitamin D has two main roles in the body:

• It maintains bone health.
• It supports the immune system.

Find out more about the health benefits of vitamin D.

Dietary sources

A person can obtain some vitamin D from the sun, but most people will also need to use other sources, too. The main alternative is food.

Dietary sources include:

• oily fish and fish oils
• fortified dairy products, plant-based milks, and cereals
• beef liver
• eggs

How can you get more vitamin D from the sun? Click here to find out.

Recommended intake

Experts measure vitamin D in international units (IU).

Current guidelines recommend that people of all ages intake of 600 IU of vitamin D daily. This is hard to measure, however, as it is not easy for a person to know how much vitamin D they obtain from sunlight.

Deficiency

A vitamin D deficiency can affect:

• older adults and children who do not spend much time out of doors
• people with darker skin
• some people with chronic health conditions
• those who live far from the Equator, where winter days are short
• those with obesity

The main effects of vitamin D deficiency include:

• osteomalacia, when bones become soft
• rickets, when a child’s bones do not develop as they should
• increased risk of infection and autoimmunity

Learn more about vitamin D deficiency.

Overdose

It is rare for a person to have too much vitamin D, but using supplements could trigger this.

Having too much vitamin D could lead to high levels of calcium in the blood.

This can lead to:

• nausea
• headaches
• low appetite and weight loss
• a buildup of calcium in tissues and blood vessels
• heart or kidney damage
• high blood pressure

Vitamin D supplements are available for purchase in pharmacies and online. A person should speak to their doctor before using these supplements, however.

Vitamin E is an antioxidant that can help the body destroy free radicals. Free radicals are unstable atoms that can cause oxidative stress. Oxidative stress can lead to cell damage, and this can result in cancer and other diseases. Vitamin E may help protect the body from a range of health issues.

Types

There are eight forms of vitamin E, but only alpha-tocopherol meets humans’ needs, according to the ODS.

Function

Some reasons why the body needs vitamin E are:

• as an antioxidant
• to boost the immune system
• to dilate blood vessels and help prevent clotting

Dietary sources

Good sources of vitamin E include:

• wheat germ oil
• sunflower seeds and oil
• almonds, hazelnuts, and peanuts
• spinach and broccoli
• kiwi fruit and mango

Which foods are good sources of vitamin E? Find out here.

Recommended intake

Current guidelines recommend people consume the following amounts of vitamin E. Experts measure vitamin E intake in milligrams (mg) AT, but packaging currently uses international units (IU).

The ODS note that, during breastfeeding, a female should consume 19 mg (28.4 IU) each day.

Deficiency

Vitamin E deficiency is rare, but it can affect people with Crohn’s disease or cystic fibrosis. These conditions affect the liver’s ability to absorb vitamin E.

A deficiency can result in:

• nerve and muscle damage that affects movement and coordination
• vision problems
• a weakened immune system

As vitamin E is an antioxidant, a long-term deficiency could increase the overall risk of various diseases.

Click here to find out how to recognize a vitamin E deficiency.

Overdose

Obtaining vitamin E through natural sources is unlikely to lead to an overdose, although supplement use can increase this risk.

People who use blood-thinning medication, such as warfarin (Coumadin) should ask their doctor before taking vitamin E supplements, as these may interfere with blood clotting.

Vitamin E supplements are available for purchase in pharmacies and online.

Vitamin K helps the body form blood clots. Blood clotting is essential to prevent excessive bleeding.

Types

There are several types of vitamin K.

The two most common groups are:

• Vitamin K-1 (phylloquinone), present in green, leafy vegetables and some other plant sources
• Vitamin K-2 (menaquinones), present in animal sources and fermented foods

There are also synthetic forms and other forms that the body makes.

Function

Apart from blood clotting, vitamin K may also:

• lower the risk of heart disease
• enhance bone health
• reduce the buildup of calcium in the blood

Learn more here about why we need vitamin K and where to get it.

Dietary sources

Food sources of vitamin K-1 and K-2 include:

• kale
• liver
• spinach
• parsley
• butter
• egg yolks

Learn about 40 foods that provide vitamin K.

Recommended intake

Experts do not have enough evidence to recommend a specific intake of vitamin K suitable to meet the needs of 97-98% of healthy individuals.

Instead, they recommend an adequate intake (AI), an amount assumed to provide nutritional adequacy, as follows:

Deficiency

The body is not able to store as much vitamin K as it does vitamin A or D. This means a person needs a regular intake of vitamin K, and there is a higher chance of a deficiency.

A vitamin K deficiency may result in:

• excess bleeding
• lower bone density, in the long term

Learn more about a vitamin K deficiency here.

Overdose

Taking high quantities of vitamin K does not appear to lead to adverse effects. However, it can interfere with the use of blood-thinning medications, such as warfarin (Coumadin).

Vitamin K supplements are available for purchase in pharmacies and online. However, people should speak to a doctor before using them, especially if they use blood thinners or have a condition that affects blood clotting.

Fat-soluble vitamins are essential for overall health. Most people can obtain enough of each vitamin from a varied and healthful diet. Anyone who has concerns about their vitamin intake should speak to a doctor.

In some cases, a doctor may recommend taking supplements.

Fat-soluble vitamins: Types, function, and sources

We include products we think are useful for our readers. If you buy through links on this page, we may earn a small commission. Here’s our process.

Fat-soluble vitamins are vitamins A, D, E, and K. They are present in foods containing fats. The body absorbs these vitamins as it does dietary fats. They do not dissolve in water.

Vitamins help the body function effectively. There are two types: water-soluble and fat-soluble vitamins. The water-soluble vitamins are vitamins B and C.

Most vitamins come from food, but sunshine contributes to vitamin D. Some people need or choose to take supplements that provide extra vitamins.

The body absorbs fat-soluble vitamins best when a person eats them with higher-fat foods.

This article looks at the types, functions, and sources of fat-soluble vitamins, and what can happen if a person has too much or too little.

Vitamin A helps maintain healthy vision. Without vitamin A, a person could experience vision problems and possibly vision loss.

Types

Vitamin A is not a single vitamin but a collection of compounds known as retinoids. Retinoids occur naturally in the human body, and they are present in some dietary sources.

Some foods provide retinols, which the body can use directly as vitamin A. Others provide provitamin A, compounds that the body converts into vitamin A.

Function

Vitamin A supports several functions throughout the body, including:

Learn more here about why we need vitamin A.

Dietary sources

People can obtain vitamin A through dietary sources.

Animal sources provide preformed vitamin A, or retinols. This type is ready for the body to use.

Plant sources provide carotenoids, such as beta-carotene, which is a powerful antioxidant. The body can convert these into vitamin A.

For this reason, lists of ingredients often show vitamin A content as “vitamin A RAE.” RAE means “retinol activity equivalents.”

Animal sources of vitamin A include:

• fish liver oil
• beef liver
• cheese, milk, and other dairy products
• Sources of beta carotene include:
• sweet potato
• kale, spinach, and other green, leafy vegetables
• carrots
• cantaloupe
• black-eyed peas
• fortified breakfast cereals

Find out more here about dietary sources of vitamin A.

Recommended intake

Nutritionists measure some vitamins in two ways:

• micrograms (mcg) RAE
• international units (IU)

Food packages usually show the amounts in IU. A diet that contains 900 mcg RAE of vitamin A, which is the recommended intake for males over 14 years of age, would provide around 3,000–36,000 IU of vitamin A, according to the Office of Dietary Supplements (ODS).

Anyone who has concerns about their vitamin A intake should seek advice from a health professional, who will help them understand these measures.

The recommended intake of vitamin A varies by age and sex.

The 2015–2020 Dietary Guidelines for Americans recommend consuming the following amounts each day. Amounts are in mcg RAE.

Deficiency

Vitamin A deficiency is rare in the United States, but it can affect a person who:

A long-term deficiency can lead to a loss of night vision and possibly a total loss of vision.

Overdose

Too much vitamin A can be toxic.

It can affect:

• people who take vitamin A supplements
• those with a high intake of fish liver oil
• people who take medications that contain retinoids, such as acitretin (Soriatane), a treatment for psoriasis

During pregnancy, high levels of vitamin A can harm a growing fetus.

Symptoms of an overdose include:

In severe cases, coma and death can result.

Vitamin A supplements are available for purchase online. However, people should speak to a doctor before taking these or other supplements.

The time a person takes a vitamin can affect its impact. Find out more here about when to take different vitamins.

People obtain vitamin D:

• naturally through exposure to sunlight or in the diet
• through fortified foods
• as supplements

The body obtains the compounds it needs to make vitamin D from food. It also produces vitamin D when ultraviolet (UV) light meets the skin.

Types

Vitamin D is not a single substance but a group of compounds collectively known as calciferol.

The body absorbs calciferol into the bloodstream and then converts it to calcitriol.

Two types occur naturally:

• vitamin D-3, found in animal fats
• vitamin D-2, found in plants, such as mushrooms

Function

Vitamin D has two main roles in the body:

• It maintains bone health.
• It supports the immune system.

Find out more about the health benefits of vitamin D.

Dietary sources

A person can obtain some vitamin D from the sun, but most people will also need to use other sources, too. The main alternative is food.

Dietary sources include:

• oily fish and fish oils
• fortified dairy products, plant-based milks, and cereals
• beef liver
• eggs

How can you get more vitamin D from the sun? Click here to find out.

Recommended intake

Experts measure vitamin D in international units (IU).

Current guidelines recommend that people of all ages intake of 600 IU of vitamin D daily. This is hard to measure, however, as it is not easy for a person to know how much vitamin D they obtain from sunlight.

Deficiency

A vitamin D deficiency can affect:

• older adults and children who do not spend much time out of doors
• people with darker skin
• some people with chronic health conditions
• those who live far from the Equator, where winter days are short
• those with obesity

The main effects of vitamin D deficiency include:

• osteomalacia, when bones become soft
• rickets, when a child’s bones do not develop as they should
• increased risk of infection and autoimmunity

Learn more about vitamin D deficiency.

Overdose

It is rare for a person to have too much vitamin D, but using supplements could trigger this.

Having too much vitamin D could lead to high levels of calcium in the blood.

This can lead to:

• nausea
• headaches
• low appetite and weight loss
• a buildup of calcium in tissues and blood vessels
• heart or kidney damage
• high blood pressure

Vitamin D supplements are available for purchase in pharmacies and online. A person should speak to their doctor before using these supplements, however.

Vitamin E is an antioxidant that can help the body destroy free radicals. Free radicals are unstable atoms that can cause oxidative stress. Oxidative stress can lead to cell damage, and this can result in cancer and other diseases. Vitamin E may help protect the body from a range of health issues.

Types

There are eight forms of vitamin E, but only alpha-tocopherol meets humans’ needs, according to the ODS.

Function

Some reasons why the body needs vitamin E are:

• as an antioxidant
• to boost the immune system
• to dilate blood vessels and help prevent clotting

Dietary sources

Good sources of vitamin E include:

• wheat germ oil
• sunflower seeds and oil
• almonds, hazelnuts, and peanuts
• spinach and broccoli
• kiwi fruit and mango

Which foods are good sources of vitamin E? Find out here.

Recommended intake

Current guidelines recommend people consume the following amounts of vitamin E. Experts measure vitamin E intake in milligrams (mg) AT, but packaging currently uses international units (IU).

The ODS note that, during breastfeeding, a female should consume 19 mg (28.4 IU) each day.

Deficiency

Vitamin E deficiency is rare, but it can affect people with Crohn’s disease or cystic fibrosis. These conditions affect the liver’s ability to absorb vitamin E.

A deficiency can result in:

• nerve and muscle damage that affects movement and coordination
• vision problems
• a weakened immune system

As vitamin E is an antioxidant, a long-term deficiency could increase the overall risk of various diseases.

Click here to find out how to recognize a vitamin E deficiency.

Overdose

Obtaining vitamin E through natural sources is unlikely to lead to an overdose, although supplement use can increase this risk.

People who use blood-thinning medication, such as warfarin (Coumadin) should ask their doctor before taking vitamin E supplements, as these may interfere with blood clotting.

Vitamin E supplements are available for purchase in pharmacies and online.

Vitamin K helps the body form blood clots. Blood clotting is essential to prevent excessive bleeding.

Types

There are several types of vitamin K.

The two most common groups are:

• Vitamin K-1 (phylloquinone), present in green, leafy vegetables and some other plant sources
• Vitamin K-2 (menaquinones), present in animal sources and fermented foods

There are also synthetic forms and other forms that the body makes.

Function

Apart from blood clotting, vitamin K may also:

• lower the risk of heart disease
• enhance bone health
• reduce the buildup of calcium in the blood

Learn more here about why we need vitamin K and where to get it.

Dietary sources

Food sources of vitamin K-1 and K-2 include:

• kale
• liver
• spinach
• parsley
• butter
• egg yolks

Learn about 40 foods that provide vitamin K.

Recommended intake

Experts do not have enough evidence to recommend a specific intake of vitamin K suitable to meet the needs of 97-98% of healthy individuals.

Instead, they recommend an adequate intake (AI), an amount assumed to provide nutritional adequacy, as follows:

Deficiency

The body is not able to store as much vitamin K as it does vitamin A or D. This means a person needs a regular intake of vitamin K, and there is a higher chance of a deficiency.

A vitamin K deficiency may result in:

• excess bleeding
• lower bone density, in the long term

Learn more about a vitamin K deficiency here.

Overdose

Taking high quantities of vitamin K does not appear to lead to adverse effects. However, it can interfere with the use of blood-thinning medications, such as warfarin (Coumadin).

Vitamin K supplements are available for purchase in pharmacies and online. However, people should speak to a doctor before using them, especially if they use blood thinners or have a condition that affects blood clotting.

Fat-soluble vitamins are essential for overall health. Most people can obtain enough of each vitamin from a varied and healthful diet. Anyone who has concerns about their vitamin intake should speak to a doctor.

In some cases, a doctor may recommend taking supplements.

Fat-soluble vitamins: Types, function, and sources

We include products we think are useful for our readers. If you buy through links on this page, we may earn a small commission. Here’s our process.

Fat-soluble vitamins are vitamins A, D, E, and K. They are present in foods containing fats. The body absorbs these vitamins as it does dietary fats. They do not dissolve in water.

Vitamins help the body function effectively. There are two types: water-soluble and fat-soluble vitamins. The water-soluble vitamins are vitamins B and C.

Most vitamins come from food, but sunshine contributes to vitamin D. Some people need or choose to take supplements that provide extra vitamins.

The body absorbs fat-soluble vitamins best when a person eats them with higher-fat foods.

This article looks at the types, functions, and sources of fat-soluble vitamins, and what can happen if a person has too much or too little.

Vitamin A helps maintain healthy vision. Without vitamin A, a person could experience vision problems and possibly vision loss.

Types

Vitamin A is not a single vitamin but a collection of compounds known as retinoids. Retinoids occur naturally in the human body, and they are present in some dietary sources.

Some foods provide retinols, which the body can use directly as vitamin A. Others provide provitamin A, compounds that the body converts into vitamin A.

Function

Vitamin A supports several functions throughout the body, including:

Learn more here about why we need vitamin A.

Dietary sources

People can obtain vitamin A through dietary sources.

Animal sources provide preformed vitamin A, or retinols. This type is ready for the body to use.

Plant sources provide carotenoids, such as beta-carotene, which is a powerful antioxidant. The body can convert these into vitamin A.

For this reason, lists of ingredients often show vitamin A content as “vitamin A RAE.” RAE means “retinol activity equivalents.”

Animal sources of vitamin A include:

• fish liver oil
• beef liver
• cheese, milk, and other dairy products
• Sources of beta carotene include:
• sweet potato
• kale, spinach, and other green, leafy vegetables
• carrots
• cantaloupe
• black-eyed peas
• fortified breakfast cereals

Find out more here about dietary sources of vitamin A.

Recommended intake

Nutritionists measure some vitamins in two ways:

• micrograms (mcg) RAE
• international units (IU)

Food packages usually show the amounts in IU. A diet that contains 900 mcg RAE of vitamin A, which is the recommended intake for males over 14 years of age, would provide around 3,000–36,000 IU of vitamin A, according to the Office of Dietary Supplements (ODS).

Anyone who has concerns about their vitamin A intake should seek advice from a health professional, who will help them understand these measures.

The recommended intake of vitamin A varies by age and sex.

The 2015–2020 Dietary Guidelines for Americans recommend consuming the following amounts each day. Amounts are in mcg RAE.

Deficiency

Vitamin A deficiency is rare in the United States, but it can affect a person who:

A long-term deficiency can lead to a loss of night vision and possibly a total loss of vision.

Overdose

Too much vitamin A can be toxic.

It can affect:

• people who take vitamin A supplements
• those with a high intake of fish liver oil
• people who take medications that contain retinoids, such as acitretin (Soriatane), a treatment for psoriasis

During pregnancy, high levels of vitamin A can harm a growing fetus.

Symptoms of an overdose include:

In severe cases, coma and death can result.

Vitamin A supplements are available for purchase online. However, people should speak to a doctor before taking these or other supplements.

The time a person takes a vitamin can affect its impact. Find out more here about when to take different vitamins.

People obtain vitamin D:

• naturally through exposure to sunlight or in the diet
• through fortified foods
• as supplements

The body obtains the compounds it needs to make vitamin D from food. It also produces vitamin D when ultraviolet (UV) light meets the skin.

Types

Vitamin D is not a single substance but a group of compounds collectively known as calciferol.

The body absorbs calciferol into the bloodstream and then converts it to calcitriol.

Two types occur naturally:

• vitamin D-3, found in animal fats
• vitamin D-2, found in plants, such as mushrooms

Function

Vitamin D has two main roles in the body:

• It maintains bone health.
• It supports the immune system.

Find out more about the health benefits of vitamin D.

Dietary sources

A person can obtain some vitamin D from the sun, but most people will also need to use other sources, too. The main alternative is food.

Dietary sources include:

• oily fish and fish oils
• fortified dairy products, plant-based milks, and cereals
• beef liver
• eggs

How can you get more vitamin D from the sun? Click here to find out.

Recommended intake

Experts measure vitamin D in international units (IU).

Current guidelines recommend that people of all ages intake of 600 IU of vitamin D daily. This is hard to measure, however, as it is not easy for a person to know how much vitamin D they obtain from sunlight.

Deficiency

A vitamin D deficiency can affect:

• older adults and children who do not spend much time out of doors
• people with darker skin
• some people with chronic health conditions
• those who live far from the Equator, where winter days are short
• those with obesity

The main effects of vitamin D deficiency include:

• osteomalacia, when bones become soft
• rickets, when a child’s bones do not develop as they should
• increased risk of infection and autoimmunity

Learn more about vitamin D deficiency.

Overdose

It is rare for a person to have too much vitamin D, but using supplements could trigger this.

Having too much vitamin D could lead to high levels of calcium in the blood.

This can lead to:

• nausea
• headaches
• low appetite and weight loss
• a buildup of calcium in tissues and blood vessels
• heart or kidney damage
• high blood pressure

Vitamin D supplements are available for purchase in pharmacies and online. A person should speak to their doctor before using these supplements, however.

Vitamin E is an antioxidant that can help the body destroy free radicals. Free radicals are unstable atoms that can cause oxidative stress. Oxidative stress can lead to cell damage, and this can result in cancer and other diseases. Vitamin E may help protect the body from a range of health issues.

Types

There are eight forms of vitamin E, but only alpha-tocopherol meets humans’ needs, according to the ODS.

Function

Some reasons why the body needs vitamin E are:

• as an antioxidant
• to boost the immune system
• to dilate blood vessels and help prevent clotting

Dietary sources

Good sources of vitamin E include:

• wheat germ oil
• sunflower seeds and oil
• almonds, hazelnuts, and peanuts
• spinach and broccoli
• kiwi fruit and mango

Which foods are good sources of vitamin E? Find out here.

Recommended intake

Current guidelines recommend people consume the following amounts of vitamin E. Experts measure vitamin E intake in milligrams (mg) AT, but packaging currently uses international units (IU).

The ODS note that, during breastfeeding, a female should consume 19 mg (28.4 IU) each day.

Deficiency

Vitamin E deficiency is rare, but it can affect people with Crohn’s disease or cystic fibrosis. These conditions affect the liver’s ability to absorb vitamin E.

A deficiency can result in:

• nerve and muscle damage that affects movement and coordination
• vision problems
• a weakened immune system

As vitamin E is an antioxidant, a long-term deficiency could increase the overall risk of various diseases.

Click here to find out how to recognize a vitamin E deficiency.

Overdose

Obtaining vitamin E through natural sources is unlikely to lead to an overdose, although supplement use can increase this risk.

People who use blood-thinning medication, such as warfarin (Coumadin) should ask their doctor before taking vitamin E supplements, as these may interfere with blood clotting.

Vitamin E supplements are available for purchase in pharmacies and online.

Vitamin K helps the body form blood clots. Blood clotting is essential to prevent excessive bleeding.

Types

There are several types of vitamin K.

The two most common groups are:

• Vitamin K-1 (phylloquinone), present in green, leafy vegetables and some other plant sources
• Vitamin K-2 (menaquinones), present in animal sources and fermented foods

There are also synthetic forms and other forms that the body makes.

Function

Apart from blood clotting, vitamin K may also:

• lower the risk of heart disease
• enhance bone health
• reduce the buildup of calcium in the blood

Learn more here about why we need vitamin K and where to get it.

Dietary sources

Food sources of vitamin K-1 and K-2 include:

• kale
• liver
• spinach
• parsley
• butter
• egg yolks

Learn about 40 foods that provide vitamin K.

Recommended intake

Experts do not have enough evidence to recommend a specific intake of vitamin K suitable to meet the needs of 97-98% of healthy individuals.

Instead, they recommend an adequate intake (AI), an amount assumed to provide nutritional adequacy, as follows:

Deficiency

The body is not able to store as much vitamin K as it does vitamin A or D. This means a person needs a regular intake of vitamin K, and there is a higher chance of a deficiency.

A vitamin K deficiency may result in:

• excess bleeding
• lower bone density, in the long term

Learn more about a vitamin K deficiency here.

Overdose

Taking high quantities of vitamin K does not appear to lead to adverse effects. However, it can interfere with the use of blood-thinning medications, such as warfarin (Coumadin).

Vitamin K supplements are available for purchase in pharmacies and online. However, people should speak to a doctor before using them, especially if they use blood thinners or have a condition that affects blood clotting.

Fat-soluble vitamins are essential for overall health. Most people can obtain enough of each vitamin from a varied and healthful diet. Anyone who has concerns about their vitamin intake should speak to a doctor.

In some cases, a doctor may recommend taking supplements.

Fat-soluble vitamins: Types, function, and sources

We include products we think are useful for our readers. If you buy through links on this page, we may earn a small commission. Here’s our process.

Fat-soluble vitamins are vitamins A, D, E, and K. They are present in foods containing fats. The body absorbs these vitamins as it does dietary fats. They do not dissolve in water.

Vitamins help the body function effectively. There are two types: water-soluble and fat-soluble vitamins. The water-soluble vitamins are vitamins B and C.

Most vitamins come from food, but sunshine contributes to vitamin D. Some people need or choose to take supplements that provide extra vitamins.

The body absorbs fat-soluble vitamins best when a person eats them with higher-fat foods.

This article looks at the types, functions, and sources of fat-soluble vitamins, and what can happen if a person has too much or too little.

Vitamin A helps maintain healthy vision. Without vitamin A, a person could experience vision problems and possibly vision loss.

Types

Vitamin A is not a single vitamin but a collection of compounds known as retinoids. Retinoids occur naturally in the human body, and they are present in some dietary sources.

Some foods provide retinols, which the body can use directly as vitamin A. Others provide provitamin A, compounds that the body converts into vitamin A.

Function

Vitamin A supports several functions throughout the body, including:

Learn more here about why we need vitamin A.

Dietary sources

People can obtain vitamin A through dietary sources.

Animal sources provide preformed vitamin A, or retinols. This type is ready for the body to use.

Plant sources provide carotenoids, such as beta-carotene, which is a powerful antioxidant. The body can convert these into vitamin A.

For this reason, lists of ingredients often show vitamin A content as “vitamin A RAE.” RAE means “retinol activity equivalents.”

Animal sources of vitamin A include:

• fish liver oil
• beef liver
• cheese, milk, and other dairy products
• Sources of beta carotene include:
• sweet potato
• kale, spinach, and other green, leafy vegetables
• carrots
• cantaloupe
• black-eyed peas
• fortified breakfast cereals

Find out more here about dietary sources of vitamin A.

Recommended intake

Nutritionists measure some vitamins in two ways:

• micrograms (mcg) RAE
• international units (IU)

Food packages usually show the amounts in IU. A diet that contains 900 mcg RAE of vitamin A, which is the recommended intake for males over 14 years of age, would provide around 3,000–36,000 IU of vitamin A, according to the Office of Dietary Supplements (ODS).

Anyone who has concerns about their vitamin A intake should seek advice from a health professional, who will help them understand these measures.

The recommended intake of vitamin A varies by age and sex.

The 2015–2020 Dietary Guidelines for Americans recommend consuming the following amounts each day. Amounts are in mcg RAE.

Deficiency

Vitamin A deficiency is rare in the United States, but it can affect a person who:

A long-term deficiency can lead to a loss of night vision and possibly a total loss of vision.

Overdose

Too much vitamin A can be toxic.

It can affect:

• people who take vitamin A supplements
• those with a high intake of fish liver oil
• people who take medications that contain retinoids, such as acitretin (Soriatane), a treatment for psoriasis

During pregnancy, high levels of vitamin A can harm a growing fetus.

Symptoms of an overdose include:

In severe cases, coma and death can result.

Vitamin A supplements are available for purchase online. However, people should speak to a doctor before taking these or other supplements.

The time a person takes a vitamin can affect its impact. Find out more here about when to take different vitamins.

People obtain vitamin D:

• naturally through exposure to sunlight or in the diet
• through fortified foods
• as supplements

The body obtains the compounds it needs to make vitamin D from food. It also produces vitamin D when ultraviolet (UV) light meets the skin.

Types

Vitamin D is not a single substance but a group of compounds collectively known as calciferol.

The body absorbs calciferol into the bloodstream and then converts it to calcitriol.

Two types occur naturally:

• vitamin D-3, found in animal fats
• vitamin D-2, found in plants, such as mushrooms

Function

Vitamin D has two main roles in the body:

• It maintains bone health.
• It supports the immune system.

Find out more about the health benefits of vitamin D.

Dietary sources

A person can obtain some vitamin D from the sun, but most people will also need to use other sources, too. The main alternative is food.

Dietary sources include:

• oily fish and fish oils
• fortified dairy products, plant-based milks, and cereals
• beef liver
• eggs

How can you get more vitamin D from the sun? Click here to find out.

Recommended intake

Experts measure vitamin D in international units (IU).

Current guidelines recommend that people of all ages intake of 600 IU of vitamin D daily. This is hard to measure, however, as it is not easy for a person to know how much vitamin D they obtain from sunlight.

Deficiency

A vitamin D deficiency can affect:

• older adults and children who do not spend much time out of doors
• people with darker skin
• some people with chronic health conditions
• those who live far from the Equator, where winter days are short
• those with obesity

The main effects of vitamin D deficiency include:

• osteomalacia, when bones become soft
• rickets, when a child’s bones do not develop as they should
• increased risk of infection and autoimmunity

Learn more about vitamin D deficiency.

Overdose

It is rare for a person to have too much vitamin D, but using supplements could trigger this.

Having too much vitamin D could lead to high levels of calcium in the blood.

This can lead to:

• nausea
• headaches
• low appetite and weight loss
• a buildup of calcium in tissues and blood vessels
• heart or kidney damage
• high blood pressure

Vitamin D supplements are available for purchase in pharmacies and online. A person should speak to their doctor before using these supplements, however.

Vitamin E is an antioxidant that can help the body destroy free radicals. Free radicals are unstable atoms that can cause oxidative stress. Oxidative stress can lead to cell damage, and this can result in cancer and other diseases. Vitamin E may help protect the body from a range of health issues.

Types

There are eight forms of vitamin E, but only alpha-tocopherol meets humans’ needs, according to the ODS.

Function

Some reasons why the body needs vitamin E are:

• as an antioxidant
• to boost the immune system
• to dilate blood vessels and help prevent clotting

Dietary sources

Good sources of vitamin E include:

• wheat germ oil
• sunflower seeds and oil
• almonds, hazelnuts, and peanuts
• spinach and broccoli
• kiwi fruit and mango

Which foods are good sources of vitamin E? Find out here.

Recommended intake

Current guidelines recommend people consume the following amounts of vitamin E. Experts measure vitamin E intake in milligrams (mg) AT, but packaging currently uses international units (IU).

The ODS note that, during breastfeeding, a female should consume 19 mg (28.4 IU) each day.

Deficiency

Vitamin E deficiency is rare, but it can affect people with Crohn’s disease or cystic fibrosis. These conditions affect the liver’s ability to absorb vitamin E.

A deficiency can result in:

• nerve and muscle damage that affects movement and coordination
• vision problems
• a weakened immune system

As vitamin E is an antioxidant, a long-term deficiency could increase the overall risk of various diseases.

Click here to find out how to recognize a vitamin E deficiency.

Overdose

Obtaining vitamin E through natural sources is unlikely to lead to an overdose, although supplement use can increase this risk.

People who use blood-thinning medication, such as warfarin (Coumadin) should ask their doctor before taking vitamin E supplements, as these may interfere with blood clotting.

Vitamin E supplements are available for purchase in pharmacies and online.

Vitamin K helps the body form blood clots. Blood clotting is essential to prevent excessive bleeding.

Types

There are several types of vitamin K.

The two most common groups are:

• Vitamin K-1 (phylloquinone), present in green, leafy vegetables and some other plant sources
• Vitamin K-2 (menaquinones), present in animal sources and fermented foods

There are also synthetic forms and other forms that the body makes.

Function

Apart from blood clotting, vitamin K may also:

• lower the risk of heart disease
• enhance bone health
• reduce the buildup of calcium in the blood

Learn more here about why we need vitamin K and where to get it.

Dietary sources

Food sources of vitamin K-1 and K-2 include:

• kale
• liver
• spinach
• parsley
• butter
• egg yolks

Learn about 40 foods that provide vitamin K.

Recommended intake

Experts do not have enough evidence to recommend a specific intake of vitamin K suitable to meet the needs of 97-98% of healthy individuals.

Instead, they recommend an adequate intake (AI), an amount assumed to provide nutritional adequacy, as follows:

Deficiency

The body is not able to store as much vitamin K as it does vitamin A or D. This means a person needs a regular intake of vitamin K, and there is a higher chance of a deficiency.

A vitamin K deficiency may result in:

• excess bleeding
• lower bone density, in the long term

Learn more about a vitamin K deficiency here.

Overdose

Taking high quantities of vitamin K does not appear to lead to adverse effects. However, it can interfere with the use of blood-thinning medications, such as warfarin (Coumadin).

Vitamin K supplements are available for purchase in pharmacies and online. However, people should speak to a doctor before using them, especially if they use blood thinners or have a condition that affects blood clotting.

Fat-soluble vitamins are essential for overall health. Most people can obtain enough of each vitamin from a varied and healthful diet. Anyone who has concerns about their vitamin intake should speak to a doctor.

In some cases, a doctor may recommend taking supplements.

Fat-soluble Vitamin Deficiencies and Inflammatory Bowel Dise… : Journal of Clinical Gastroenterology

Background: 

Vitamin deficiency is frequently associated with inflammatory bowel disease (IBD). Supplementation of vitamins could thus serve as an adjunctive therapy. The present meta-analysis reviews the deficiencies and alterations in serum fat-soluble vitamins (A, D, E, and K) reported in IBD patients.

Materials and Methods: 

PubMed database search was performed to identify all primary studies up to January 2015 that evaluated the serum concentrations of fat-soluble vitamin levels in IBD patients compared with healthy individuals. We estimated pooled mean differences between groups and estimated their relations with some compounding variables (age, disease duration, C-reactive protein, albumin), using a meta-regression analysis.

Results: 

Nineteen case-control studies met selection criteria. In patients with Crohn’s disease (CD), vitamin A, D, E, K status was lower than in controls [D=212 μg/L.92; 95% confidence interval (CI), 95.36-330.48 μg/L, P=0.0002; D=6.97 nmol/L, 95% CI, 1.61-12.32 nmol/L, P=0.01; D=4.72 μmol/L, 95% CI, 1.60-7.84 μmol/L, P=0.003; D=1.46 ng/mL, 95% CI, 0.48-2.43 ng/mL, P=0.003, respectively]. Patients with ulcerative colitis had lower levels of vitamin A than controls (D=223.22 μg/L, 95% CI, 44.32-402.12 μg/L, P=0.01). Patients suffering from CD for a longer time had lower levels of vitamins A (95% CI=7.1-67.58 y, P=0.02) and K (95% CI, 0.09-0.71 y, P=0.02). Meta-regression analysis demonstrated statistically significant associations between the levels of inflammatory biomarkers: C-reactive protein (P=0.03, 95% CI, −9.74 to −0.6 mgl/L) and albumin (P=0.0003, 95% CI, 402.76-1361.98 g/dL), and vitamin A status in CD patients.

Conclusion: 

Our meta-analysis shows that the levels of fat-soluble vitamins are generally lower in patients with inflammatory bowel diseases and their supplementation is undoubtedly indicated.

90,000 A, D, E and K. What does fat-soluble vitamins mean? What vitamins is fat-soluble

Most vitamins are classified based on their solubility. Thus, one category may be water-soluble and the other fat-soluble. It is important to note that the second category has some similarities to oils and cannot be dissolved in water.

Unlike water-soluble vitamins, fat-soluble microelements are much better absorbed by the body, especially when consumed simultaneously with food.It is worth noting that these vitamins, which include K, D, A and E, are found in the diet of almost every person.

Let’s consider the useful properties of these substances, their effect on the human body and the main sources of production.

What you need to know about vitamin A

Vitamin A is used by the human body in order to ensure the normal functioning of the eyes, as well as to maintain visual acuity. In the absence of this trace element in the body, people would not be able to see.

Varieties of vitamin A

This trace element often does not act as an independent substance, but is presented in the form of fat-soluble compounds called retinoids. The most common compound is retinol, which is also considered the dietary form of vitamin A. Among other types of compounds, the following are distinguished:

90 020 90 021 retina;

These compounds are present in the human body, but are extremely rare in food.

Another form of the vitamin is 3.4-dehydroretinal, which is better known as vitamin A2. This compound has a relatively low activity and is found in freshwater fish.

The value of vitamin A for the body

This vitamin is extremely useful for the human body, as it is used by a number of organs to perform certain functions, namely for:

• formation of tear fluid, which protects the organs of vision;
• normalization of sensitivity to light;
• strengthening the immune system;

90,021 cell growth in a young organism;

90,021 hair growth on the head;

90,021 fertility support;

• for the normal development of the fetus in pregnant women.

Main sources of vitamin A

It should be noted that vitamin A can only be obtained from animal products. Among the foods with the highest content of this microelement are animal liver, fish oil and butter.

The amount of this vitamin in 100 grams of the product is shown below.

However, it should be noted that this trace element can also be obtained from carotenoid antioxidants, which can be found in some plant species.These elements are also often called provitamin A.

The most effective provitamin is beta-carotene, which can be obtained by adding spinach, cabbage and carrots to your diet.

Recommendations for use

The table below shows the daily amount of vitamin A required to normalize body functions. This amount, abbreviated as RDA, represents the daily value for this micronutrient, which is suitable for 97.5 percent of the population.

Among other things, this table shows the maximum allowable dosage of this vitamin, which is absolutely safe for most people without chronic or serious diseases, which is listed as UL.

Lack of vitamin A and its consequences

Acute vitamin A deficiency is extremely rare.However, it can often be seen in vegetarians, since they do not consume animal products that are high in this micronutrient.

Despite the fact that plant foods containing carotenoids are often consumed by vegans, they do not always contribute to the production of retinol, which is the active form of vitamin A. This is primarily due to human genetics and individual characteristics of the body.

A deficiency of this trace element is also common in developing countries, where the amount of food containing the corresponding compound is limited.Severe vitamin A deficiencies are most common in cities and countries where the staple foods are potatoes, rice and cassava.

The first sign of a mild deficiency of this trace element is visual impairment at night. At the same time, vitamin A deficiency over a long period of time can lead to the following negative consequences:

• the development of xerophthalmia – a disease associated with a decrease in the production of tear fluid and an increase in dry eyes;
• total blindness, the only type of blindness that can be prevented by adding fat-soluble vitamin A foods to the diet;

90,021 hair loss;

• development of hyperkeratosis – a skin disease in the form of a rash resembling the effect of “goose bumps”;
• impairment of the immune system.

What an overdose of vitamin A can lead to

Excessive intake of vitamin A can lead to hypervitaminosis, which in some cases can have serious consequences for the body. In most cases, hypervitaminosis is associated with frequent consumption of fish oil, liver, or specialized dietary supplements. At the same time, the use of provitamins A in any amount is not able to cause a similar effect.

In case of excessive consumption of this compound, people may experience the following symptoms:

• increased fatigue;

90,021 irritability;

90,021 headache;

• inflammatory processes in the oral cavity;
• blurred vision;

90,021 joint pain;

90,021 pain in the abdomen;

90,021 appetite disorders;

90,021 skin rashes.

In addition to all of the above, abuse of this vitamin can lead to bone loss, liver dysfunction, and hair loss. The use of very large doses can even lead to death.

The maximum daily intake of vitamin A for an average adult is considered to be 900 mcg per day, and in children it is several times lower. When using this trace element, you should also take into account the individual characteristics of the body.So, people with liver disease should be extremely careful when taking this compound.

Women during pregnancy should be no less careful, for whom the daily intake of vitamin A should not exceed 700 mcg per day, since a larger amount can be dangerous to the fetus and cause birth defects in the child.

Benefits of using vitamin A supplements

Taking supplements high in this micronutrient is extremely beneficial for people who are deficient in vitamin A.If the amount of this microelement contained in the human diet is sufficient to normalize the functions of the body, then there is no urgent need to take additional drugs.

However, scientists were able to establish that the use of specialized nutritional supplements by people in whose diet is sufficient vitamin A, despite the absence of a deficiency, improved their health. Thus, the use of supplements with a high content of this trace element made it possible to speed up the process of treating measles.In addition, the researchers found that this compound can reduce the risk of death from this disease by 50-80 percent. They also noted that vitamin A suppresses the measles virus.

The most important thing about vitamin A

Vitamin A, also known as retinol, is a fat-soluble vitamin. This element is able to have a positive effect on vision and a number of other organs.

This element can be obtained by consuming butter, fish oil, liver and plant products containing provitamin A.

Lack of this trace element is extremely rare. Most often, people who follow a diet based on plant products, as well as people who do not have animal fats in their diet, suffer from a deficiency of this compound.

The first symptom of a deficiency of this vitamin is visual impairment at night. At the same time, vitamin A deficiency over a long period can lead to blindness.

Despite the fact that the use of this vitamin is necessary, its excessive consumption is highly undesirable, especially for pregnant women.

What you need to know about vitamin D

Vitamin D, known in many countries of the world as the “sunshine vitamin”, is generated by the human skin when exposed to sunlight. This element is considered very beneficial for strengthening bones. It should be noted that its deficiency in most cases leads to increased bone fragility.

Varieties of vitamin D

“Sun Vitamin” is a collective term that simultaneously implies several fat-soluble compounds that are similar to each other.However, the most famous compound is calciferol.

As of today, this vitamin is distributed in two forms:

• ergocalciferol, also known as vitamin D2, produced from mushrooms and certain other plants;
• Cholecalciferol, known as D3, found in animal products.

It should be noted that it is cholecalciferol that is produced by human skin under the influence of ultraviolet radiation.

The value of vitamin D for the body

According to scientists, this vitamin is very beneficial for humans. However, researchers were able to find scientific confirmation of only a few beneficial properties of this trace element, which include:

• Strengthening bones by regulating the level of phosphorus and calcium in the blood, which are the main elements necessary for the formation and growth of bone tissue;
• Improving the immune system.

Calcitriol, the active form of vitamin D, is produced by the liver and kidneys after calciferol is absorbed. It is important to note that this element can be converted into calcidiol, which accumulates in cells and is used by the body when needed.

Main sources of vitamin D

Under the condition of regular exposure to ultraviolet radiation on the human skin, a sufficient amount of vitamin D is formed in the body.

Today people spend relatively little time under the sun or are completely dressed in clothes.Some people use sunscreen. All this leads to a decrease in the amount of vitamin D produced by the skin.

That is why people are increasingly striving to include this trace element in their diet and use it along with food. It should be borne in mind that only some products contain this element. These include:

• oily fish;

90,021 fish oil;

90,021 mushrooms.

In the table below, you can see the amount of vitamin D in 100 grams of foods with the highest content of this trace element:

Also in stores you can often find some dairy products with added vitamin D.

Recommendations for use

In the table below, you can find the recommended amount of vitamin D per day for people of different age groups, as well as the maximum allowable intake of this substance.

Due to the fact that the RDA for infants has not been provided by any research group, the values ​​marked with an asterisk below are the recommended values.

Vitamin D deficiency and its consequences

Acute vitamin D deficiency is considered quite rare, but a slight deficiency of this element is very common, especially among the elderly and people who have recently undergone surgery.

The most common causes of a deficiency of this element include:

90,020 90,021 old age;

90,021 dark skin color;

90,021 obesity;

90,021 diseases that impair the absorption of fat.

The most common symptoms of vitamin D deficiency are increased bone fragility, decreased muscle tone and increased risk of fractures. This condition is called rickets in children, and osteomalacia in adults.

Often, a lack of this vitamin is accompanied by a deterioration in the immune system, hair loss, increased fatigue, and a violation of the tissue regeneration process.

Scientists note that people who are deficient in vitamin D also significantly increase the risk of developing cardiovascular diseases and the risk of death associated with cancer.

What an overdose of vitamin D can lead to

An excess of this vitamin in the human body is very rare, since excessive exposure to the sun is not able to cause a similar effect.However, overuse of food additives can harm the body.

Excessive intake of vitamin D can cause hypercalcemia, a disease associated with excessively high levels of calcium in the blood. This disease is often accompanied by the following symptoms:

• nausea;

90,021 appetite disorders;

90,021 disruption of the heart and kidneys;

• high blood pressure;

90,021 headache;

• fetal developmental disorders in pregnant women.

Experts recommend using no more than 4000 ME per day for people without any diseases. It is important to take into account that smaller amounts of this substance can harm children. Symptoms of overconsumption of vitamin D may take several months to appear.

Benefits of using vitamin D supplements

Food supplements with a high content of this microelement are recommended for people who do not receive enough ultraviolet radiation, as well as for those who do not eat fatty fish and liver.Supplements are equally beneficial for hospitalized and elderly people.

Scientists noted that vitamin D intake also helps to eliminate infections that cause respiratory distress.

The most important thing about vitamin D

Vitamin D is often called “solar” because it is generated by the human skin when UV radiation hits its surface.

At the same time, today a fairly large number of people do not receive the required amount of this microelement for one reason or another.Therefore, to replenish it, they need to take specialized nutritional supplements or add foods high in this substance to their diet.

Currently, the main sources of vitamin D are mushrooms, fish oil and oily fish.

Acute lack of this element can lead to the development of rickets in children and osteomalacia in adults.

What you need to know about vitamin E

Vitamin E has antioxidant properties and protects cells from the negative effects of free radicals and premature aging.

Varieties of vitamin E

The name of this trace element means a family of antioxidants, consisting of eight elements, which has a conditional division into several groups:

• tocopherols, which include alpha, beta, gamma, and delta tocopherol;

90,021 tocotrienols, which include alpha, beta, gamma, and delta tocotrienol.

The most common of the above antioxidants is alpha-tocopherol.Its amount is approximately 90 percent of the total amount of vitamin E in the blood.

The value of vitamin E for the body

The main task of vitamin E is to reduce oxidative stress and protect the fatty acids contained in cells from the negative effects of free radicals. The effectiveness of this antioxidant increases if it interacts with selenium, as well as vitamins B3 and C.

When a large amount of vitamin E is consumed, blood clotting is significantly reduced, which is why it can be used as a blood thinner.

Main sources of vitamin E

Nuts, seeds and some varieties of vegetable oils have the highest concentration of this vitamin among common foodstuffs. Below is a table listing the foods with the highest concentration of this antioxidant.

Other sources of vitamin E include peanut butter, fish oil, oily fish and margarine.

Recommendations for use

In the table below, you can see the daily intake of vitamin E for different age groups, as well as the maximum allowable intake, which is harmless to human health.Due to the fact that scientists were not able to identify the rate of consumption of this substance for infants, the values ​​marked with an asterisk are arbitrary.

Vitamin E deficiency and its consequences

Lack of this vitamin is very rare.Moreover, a deficiency of this substance has never been observed in healthy people.

Most of the deficiencies are caused by diseases that impair the absorption of fat, one of which is cystic fibrosis. Liver diseases are also among the causes of vitamin E deficiency.

The lack of this trace element in the body is accompanied by the following symptoms:

• Decreased muscle endurance;

90,021 tremors;

90,021 visual impairment;

• numbness of the limbs;
• impairment of the immune system;
• Difficulty moving.

The presence of vitamin E deficiency over a long period of time can lead to the development of anemia, cardiovascular diseases, neurological diseases, dementia, impaired reflexes and blindness.

What an overdose of vitamin E can lead to

When using food as a source of vitamin E, an overdose of this element is practically impossible. Cases of vitamin E poisoning have been reported when a person ingested excessive amounts of dietary supplements.And even so, an overdose of the substance is considered relatively harmless compared to vitamins A and D.

Excessive intake of vitamin E can reduce blood clotting and cause severe bleeding if cuts or skin breaks occur. In this regard, the intake of a trace element is undesirable in combination with drugs that thin the blood.

Provided that more than 1000 micrograms of vitamin E are consumed per day, this antioxidant changes its properties and begins to act like free radicals – it begins to destroy cells.

According to research by scientists, high levels of this trace element, even in the absence of symptoms caused by an overdose, can be harmful to the body. So, during the research, scientists found that the use of dietary supplements with this vitamin can increase the risk of developing prostate cancer, as well as the risk of death.

Benefits of Using Vitamin E Food Supplements

Consumption of large amounts of this vitamin can improve health.Thus, the use of gamma-tocopherol can increase the volume of blood vessels, thereby reducing blood pressure and the risk of cardiovascular diseases. In addition, this vitamin is able to reduce the level of “bad” cholesterol.

The most important thing about vitamin E

Vitamin E includes many antioxidants that have a positive effect on the human body. The most common of these is alpha-tocopherol.

The most common foods high in vitamin E are nuts, seeds, and some types of vegetable oils.

Acute deficiency of this substance is extremely rare.

Although vitamin E supplementation can improve the health of the body, scientists differ on its benefits due to the possible risks associated with excessive consumption of this substance.

What you need to know about vitamin K

This trace element is responsible for blood clotting, and without its presence in the body, you can bleed and be fatal.It comes in several forms.

Varieties of vitamin K

Vitamin K combines several compounds of the fat-soluble type. It is customary to distinguish two main groups:

• K1, or phylloquinone – found in plant products, acts as the main vitamin form required by the human body;
• K2, or menaquinone – found in animal products, fermented soy products. In the human body, its production occurs in the large intestine with the help of bacteria.

There are also three artificial forms of vitamin K in the form of menadione (K3), menadiol diacetate (K4) and vitamin K5.

The value of vitamin K for the body

The process of blood clotting is not realized without this trace element. The very name of vitamin K comes from the word “coagulation”, that is, coagulation. Nevertheless, it is also necessary for performing other important functions, in particular, strengthening the bone apparatus, preventing vascular calcification, and reducing the risk of developing heart defects.

Basic sources of vitamin K

Trace element K1 is found in leafy green vegetables, but various animal products and fermented soy products are enriched with the K2 form.

Menaquinone, in comparison with phylloquinone, is contained only in some products, and even in small quantities – these are egg yolks, liver and butter. It can be found in some soy products, including natto.

Recommendations for use

Below is a table with the recommended intake of vitamin K.AI is very similar to RDA, but with weaker data.

Vitamin K deficiency and its consequences

If other fat-soluble vitamins accumulate in the body, thus forming valuable reserves, then there is no vitamin K, therefore, the lack of it in the framework of your diet and food consumption can lead to an acute shortage in a short period of time.

The greatest health risks are experienced by people who have poor or no fat absorption in the body. This group also includes people with celiac disease, inflammatory bowel disease and cystic fibrosis.

The use of broad-spectrum antibiotics also increases the risk of micronutrient deficiencies. Another reason for this phenomenon may be an overdose of vitamin A, which interferes with normal absorption.

With excessive consumption and even abuse of vitamin E, there is resistance to the effect of vitamin K, which disrupts the process of blood clotting.

In the absence of vitamin K, the blood will not clot, even the smallest and smallest wound will provoke severe bleeding.

A deficiency of this trace element is a rather rare occurrence, since the body needs a very small amount of a substance for the clotting process to occur correctly.

If the content of vitamin K in the human body is low, it reduces bone density, increases the risk of fractures, especially in women.

What an overdose of vitamin K can lead to

Natural forms of this microelement are not characterized by toxicity, which is typical for other fat-soluble vitamins.

Scientists conducted various studies, but could not calculate the acceptable limit for the consumption of the substance. It is necessary to carry out more experiments and experiments.

If we talk about menadione – vitamin K3, then if the recommended dosage is exceeded, unwanted side effects may occur.

Benefits of using vitamin K supplements

Specialists conducted controlled studies to study the effects of vitamin K supplementation on the human body.It was possible to find out that the use of such drugs, which contain K1 and K2, has a beneficial effect on the bone apparatus, protects against fractures, and allows not to lose bone mass.

When using K2 up to 90 mg per day, it helps patients with liver cancer live longer.

In the framework of observational studies, scientists have found that taking vitamin K2 significantly reduces the risk of heart disease. However, such experiments do not have sufficient justification, and they are also limited.

It is known that a 3-year intake of vitamin K1 supplements in the amount of 0.5 mcg daily slows the development of insulin resistance in older men, but experience in women has not shown any difference with taking a placebo pill.

The most important thing about vitamin K

Vitamin K combines several compounds of a fat-soluble type, is divided into two main substances – K1, or phylloquinone, and K2, or menaquinone. The former is fortified with leafy green vegetables, while the latter is found in animal or soy foods.

A small amount of vitamin K is produced in the human intestine by bacteria.

Due to a deficiency of a trace element, blood ceases to coagulate, there is a risk of excessive loss of it.

The beneficial properties of vitamin K supplements are limited due to the small amount and lack of validity of the studies carried out. However, according to some studies, it is very beneficial for heart and bone health.

General conclusion

To maintain the proper functioning of the body, a person needs to eat foods with such fat-soluble vitamins as A, K, E and D.The first three are easily obtained from foods that are included in the daily diet, in particular nuts, seeds and seeds, fish, vegetables and eggs.

In most cases, it is fatty foods that are saturated with these useful microelements, and their absorption can be accelerated and improved if combined with low-lipid foods.

Some foods contain vitamin D – this is in fish and its fat. In addition, this substance is produced on the skin when exposed to sunlight.

In view of the above, vitamin D deficiency acts as an acute problem of modern mankind, and the reason is non-observance of the proper diet, staying in the sun for a minimum amount of time.

If you want to take supplements with fat-soluble vitamins, it is very useful to combine them with vitamin D.

The body will be completely healthy only if it receives all the vitamins in the right doses.

Research References

1. Effect of consumption of the nutrient-dense, freshwater small fish Amblypharyngodon mola on biochemical indicators of vitamin A status in Bangladeshi children: a randomized, controlled study of efficacy.

https://www.ncbi.nlm.nih.gov/pubmed/17925053

2. Get Ready for FoodData Central, a New USDA Food and Nutrient Data System

https://ndb.nal.usda.gov/ndb/

3. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc.

https://www.ncbi.nlm.nih.gov/pubmed/25057538

90,000 Are you getting enough of these fat-soluble vitamins? – Blog

Posted by Erik Madrid, MD

In this article:

At the beginning of the 20th century, it was believed that humans only needed four types of nutrients: proteins, carbohydrates, fats, and minerals.Since then, our understanding of health and nutritional needs has changed significantly. This is especially true when it comes to preventing disease, chronic illness and general disability.

In terms of health, we were able to understand an important thing: an acute deficiency of some vitamins can lead to known diseases such as:

mostly eliminated.More recently, however, we learned that a person’s unique genetics, lifestyle, exposure to environmental toxins, and antioxidant intake all contribute to some people’s unique needs for certain vitamins and minerals, sometimes higher than those of others. In addition, the absence of certain diseases does not mean that a person is meeting their nutritional needs.

Each of us falls into one of three categories:

• you are deficient in one or more nutrients;
• You have enough of all the nutrients you need at any given time;
• You have an excess of one or more specific nutrients that will either be stored or excreted.

The first scenario needs attention. According to a 2006 report by the World Health Organization (WHO), one in three people worldwide is deficient in various vitamins and / or minerals. This is a problem that can affect generations. When children and pregnant women suffer from vitamin deficiencies, the long-term health consequences can be severe. Vitamin deficiency isn’t just among underweight people – overweight and obese people can also have significant nutritional deficiencies.

Fat-soluble vitamins versus water-soluble vitamins

Vitamins are divided into two main groups: fat-soluble and water-soluble. Water-soluble vitamins are so named because they dissolve in water. This means that they are usually not stored in the body and must come from outside. This distinguishes them from fat-soluble vitamins, which are absorbed through fats.

Vitamin A

Vitamin A is an energy nutrient. At the same time, the deficiency of this vitamin is the most widespread vitamin deficiency in the world. It is a powerful antioxidant that comes in two forms: provitamin A is found in plants and associated vitamin A is found in animal products.

Lack of vitamin A in the human diet can be disastrous, especially in children.Vitamin A is essential for good vision, strong immunity and future reproductive health. According to the World Health Organization, more than 250 million preschool children worldwide are deficient in vitamin A. Pregnant women with vitamin A deficiency are at risk of night blindness, and if the fetus is deficient in vitamin A, there is a risk of developmental disorders.

Risk Factors for Vitamin A Deficiency

• Low Dairy and Egg Diet
• Insufficient Fruit Consumption
• Few Vegetables in the Diet

Many plant foods contain beta-carotene, a precursor of vitamin A.These carotenoids, as they are called, are very important for overall health.

Symptoms and complications of vitamin A deficiency

• Blindness and night blindness
• Diarrhea
• Dry flaky skin
• Increased risk of infection
• Increased risk of miscarriage

multivitamins with vitamin A, and in some cases you may need vitamin A as a separate supplement.However, this should be discussed with your doctor first.

Vitamin A can become toxic when consumed in excess of 25,000 IU or more of bound vitamin A daily.

Vitamin A is also believed to interact with the beneficial effects of vitamin D when consumed in excess. Beta-carotene has no known toxic effects or restrictions on the maximum allowable amount for consumption. However, when beta-carotene is consumed in large quantities, some people may temporarily turn orange tinge to the skin, a condition called beta-carotenemia.

Smokers should be especially careful when taking vitamin A as it can increase the risk of lung cancer, according to some studies. Talk to your doctor first before taking this vitamin.

Vitamin D

Thousands of studies over the past ten years confirm the benefits of vitamin D when taken correctly. These studies show that people with higher levels of vitamin D in their blood have a lower risk of heart attack, breast cancer, colon cancer, multiple sclerosis, type 1 and 2 diabetes, hypertension, and other ailments.

Vitamin D deficiency is common. Even in my medical practice (and I work in Southern California, where sunny weather is more than 300 days a year), four out of five (80%) patients have a clinical vitamin D deficiency, determined by a blood level of 30 ng / ml (75 nmol / L ) or lower.

Low vitamin D levels are associated with an increased risk of these diseases and disorders:

• Autism
• Autoimmune diseases
• Dementia
• Fibromyalgia
• Heart disease / hypertension
• Cancer (colon, ovarian prostate)
• Osteopenia and osteoporosis
• Stroke, heart and peripheral arterial disease

Adequate exposure to sunlight is important for overall health and wellness.Most adults who are deficient in vitamin D need to take vitamin D (cholecalciferol) at a daily dosage of 2000-5000 IU. Someone may need more.

Pregnant and breastfeeding women should also consider taking 5000 IU vitamin D supplements per day. Vitamin D can be taken by most healthy children between the ages of 1 and 18. The usual dosage is 1,000 to 2,000 IU per day.

Vitamin E (α-tocopherol)

Vitamin E can be stored not only in the liver, but also in adipose tissue.It provides antioxidant protection against free radicals, and when vitamin E is deficient, there is an increased risk of increased cellular oxidation and damage to nerve fibers. Many doctors believe that vitamin E deficiency is generally rare, but recent research casts doubt on this ingrained opinion.

A 2019 study from Asia and published in the International Journal of Vitamin and Nutrition Research estimates that vitamin E deficiency affects up to 67% of infants, 80% of children, 56% of adolescents, and up to 72% of older adults and pregnant women.In addition, a 2015 study by South Korean scientists found that 23% of people between the ages of 20 and 59 had insufficient levels of vitamin E (α-tocopherol). Finally, in a 2006 US study of children aged 2 to 5 years, 68% of American children were deficient in vitamin E.

Causes and risks of vitamin E deficiency

• Premature birth
• See list below)
• Malabsorption syndromes (leaky gut, celiac disease, Crohn’s disease, ulcerative colitis)
• Familial isolated vitamin E deficiency (rare genetic disease)

Vitamin E deficiency symptoms

• Neurological and brain disorders
• Neuropathy
• Anemia
• Fatigue
• Weakness in muscles
• Visual impairment (retinopathy)
• Immune system failures

Food sources of vitamin E

• Fish and seafood, Atlantic fish
• Nuts (almonds, hazelnuts, peanuts, peanuts)
• Seeds (sunflower seeds)
• Green leafy vegetables (spinach, cabbage, broccoli, red bell pepper)
• Wheat germ oil
• Avocados

When vitamins there is not enough food, daily intake m of quality multivitamins will help ensure you get enough vitamin E.When that is not enough, individual vitamin E supplements can be taken at a dosage of 200-400 IU per day. Most people are advised not to take more than 1000 IU of vitamin E per day.

Vitamin K

Vitamin K is a fat-soluble vitamin that is very important for strong bones, normal brain function and blood formation in general. Vitamin K is available in three forms:

• Vitamin K1 (phylloquinone)
• Vitamin K2 (menaquinone)
• Vitamin K3 (menaquinone)

Vitamin K1 is found mainly in green leafy vegetables, and vitamin K2 is usually bacterial (intestinal bacteria) in origin, and also comes from fermented foods and animal products such as meat and dairy products.Vitamin K3 is synthetically made and is found in some dietary supplements.

Many beneficial bacteria that live in our gut (gut microbiome) can produce vitamin K2. When a person takes antibiotics, vitamin K2 production can be disrupted due to the death of the beneficial bacteria by the antibiotic. It is believed that this may be the main reason for a possible change in blood viscosity in patients taking the anticoagulant Coumadin (warfarin) while taking certain medications or with an abnormally high content of green leafy vegetables in the diet.

People with low blood levels of vitamin K are also at higher risk of weakened bones (osteopenia, osteoporosis). Low vitamin K levels have also been linked to an increased risk of heart disease, and this is probably also indicative of the health benefits of green leafy vegetables for the heart and blood vessels.

Risks and causes of vitamin K deficiency

• Newborns are at increased risk of vitamin K deficiency (which is why many maternity hospitals around the world are injected with vitamin K at birth)
• See list below)
• Weight loss surgery (bariatric)
• Malabsorption syndromes (leaky gut, celiac disease, Crohn’s disease, ulcerative colitis)
• Chronic or frequent use of antibiotics

Vitamin K deficiency symptoms