What is vitamin D and why is it important for your health. How much vitamin D do you need daily. Which foods are rich in vitamin D. Can you get vitamin D from sunlight. What types of vitamin D supplements are available. How to determine if you’re getting enough vitamin D.

The Vital Role of Vitamin D in Human Health

Vitamin D is a crucial nutrient that plays a significant role in maintaining overall health and well-being. It is primarily known for its importance in bone health, but its functions extend far beyond that. Let’s explore the various aspects of this essential vitamin and understand why it’s so important for our bodies.

Key Functions of Vitamin D

• Promotes calcium absorption for strong bones
• Supports muscle function
• Facilitates nerve signal transmission
• Boosts immune system function

How does vitamin D contribute to bone health? Vitamin D works in tandem with calcium to build and maintain strong bones. It enhances the absorption of calcium in the intestines, ensuring that your body can utilize this mineral effectively. This synergy between vitamin D and calcium is crucial in preventing osteoporosis, a condition characterized by weakened and brittle bones.

Beyond bone health, vitamin D is essential for various bodily functions. It plays a vital role in muscle movement, helping to maintain strength and reduce the risk of falls, especially in older adults. Additionally, vitamin D is crucial for proper nerve function, enabling efficient communication between your brain and body.

One of the lesser-known but equally important functions of vitamin D is its role in supporting the immune system. Adequate levels of vitamin D help your body defend against invading pathogens, including bacteria and viruses. This immune-boosting property has garnered increased attention in recent years, particularly in the context of overall health and disease prevention.

Recommended Daily Intake of Vitamin D

The amount of vitamin D you need each day varies depending on your age. The following table outlines the average daily recommended amounts:

Why do older adults need more vitamin D? As we age, our skin becomes less efficient at producing vitamin D from sunlight exposure. Additionally, older adults may spend less time outdoors and have reduced dietary intake of vitamin D-rich foods. To compensate for these factors and maintain optimal bone health, the recommended daily intake for adults over 71 years is increased to 20 mcg (800 IU).

Dietary Sources of Vitamin D

While vitamin D is not naturally abundant in many foods, there are several dietary sources that can help you meet your daily requirements. Understanding these sources is crucial for maintaining adequate vitamin D levels, especially for individuals with limited sun exposure or those at risk of deficiency.

Natural Sources of Vitamin D

• Fatty fish (trout, salmon, tuna, mackerel)
• Fish liver oils
• Beef liver
• Egg yolks
• Cheese
• Mushrooms (especially those exposed to UV light)

Which foods are the best natural sources of vitamin D? Fatty fish and fish liver oils stand out as excellent natural sources of vitamin D. For example, a 3-ounce serving of cooked salmon can provide about 15 mcg (600 IU) of vitamin D, which meets the daily requirement for most adults. Other fish like trout, tuna, and mackerel also offer significant amounts of this vital nutrient.

Fortified Foods

In the United States, fortified foods provide a substantial portion of dietary vitamin D. These include:

• Milk (about 3 mcg or 120 IU per cup)
• Plant-based milk alternatives (soy, almond, oat milk)
• Breakfast cereals
• Some brands of orange juice
• Yogurt
• Margarine

Why are foods fortified with vitamin D? Food fortification began in the 1930s as a public health measure to combat rickets, a bone-weakening disease caused by severe vitamin D deficiency. Today, it continues to play a crucial role in helping populations meet their vitamin D requirements, especially in regions with limited sunlight exposure.

It’s important to note that while milk is commonly fortified, products made from milk, such as cheese and ice cream, are usually not fortified with vitamin D. Always check the Nutrition Facts label to determine the vitamin D content of a food or beverage.

Sunlight and Vitamin D Synthesis

One of the unique aspects of vitamin D is that our bodies can produce it when our skin is exposed to sunlight. This process has led to vitamin D being dubbed the “sunshine vitamin.” However, relying solely on sun exposure for vitamin D can be complex and comes with certain considerations.

Factors Affecting Vitamin D Synthesis from Sunlight

• Cloud cover and smog
• Skin pigmentation
• Age
• Use of sunscreen
• Time of day and season
• Latitude

How does skin color affect vitamin D production? Individuals with darker skin have higher levels of melanin, which acts as a natural sunscreen. While this provides greater protection against skin damage and cancer, it also reduces the skin’s ability to produce vitamin D from sunlight. As a result, people with darker skin may need longer sun exposure or may need to rely more on dietary sources and supplements to maintain adequate vitamin D levels.

Is it possible to get enough vitamin D from sunlight alone? While it is possible for some individuals to meet their vitamin D needs through sunlight exposure, it’s not recommended as the sole source due to the risk of skin damage and cancer from excessive UV radiation. The amount of vitamin D produced through sun exposure can vary greatly depending on factors such as time of day, season, latitude, and individual characteristics.

Health experts generally recommend limiting direct sun exposure and using sunscreen with an SPF of 15 or higher when spending extended time outdoors. While sunscreen does reduce vitamin D production in the skin, the protection it offers against skin cancer outweighs this drawback. To ensure adequate vitamin D levels, a combination of safe sun exposure, dietary sources, and supplements (if necessary) is often the best approach.

Vitamin D Supplements: Types and Considerations

For individuals who struggle to meet their vitamin D needs through diet and safe sun exposure alone, supplements can be a valuable option. Understanding the different types of vitamin D supplements and how to use them effectively is crucial for maintaining optimal health.

Forms of Vitamin D Supplements

• Vitamin D2 (ergocalciferol)
• Vitamin D3 (cholecalciferol)

What’s the difference between vitamin D2 and D3 supplements? Both forms can effectively increase vitamin D levels in the blood. However, vitamin D3 is generally considered more potent and may raise blood levels higher and for a longer duration compared to D2. Vitamin D3 is the form naturally produced in human skin in response to sunlight, while D2 is derived from plant sources.

Vitamin D supplements are available in various formulations, including:

• Multivitamin/multimineral supplements
• Standalone vitamin D supplements
• Combination supplements (vitamin D with calcium or other nutrients)

How should vitamin D supplements be taken for optimal absorption? Since vitamin D is fat-soluble, it’s best absorbed when taken with a meal or snack that contains some fat. This helps to enhance the absorption of the vitamin in the digestive tract.

It’s important to note that while supplements can be beneficial, they should not be used as a substitute for a healthy diet. Always consult with a healthcare professional before starting any new supplement regimen, especially if you have underlying health conditions or are taking medications.

Assessing Vitamin D Status

Given the importance of vitamin D for overall health, it’s crucial to ensure that you’re getting enough. But how can you tell if your vitamin D levels are adequate? The most reliable method is through a blood test that measures the concentration of 25-hydroxyvitamin D in your blood.

Interpreting Vitamin D Blood Levels

• Adequate: 50 nmol/L (20 ng/mL) or above
• Deficient: Below 30 nmol/L (12 ng/mL)
• Potentially harmful: Above 125 nmol/L (50 ng/mL)

Why is 25-hydroxyvitamin D used to measure vitamin D status? This form of vitamin D is the main circulating form in the bloodstream and provides the best indication of vitamin D status. It reflects the total amount of vitamin D from all sources – diet, supplements, and sun exposure.

In the United States, most people have adequate blood levels of vitamin D. However, it’s estimated that nearly one in four individuals have vitamin D levels that are too low or inadequate for bone and overall health. Certain groups are at higher risk of vitamin D deficiency, including:

• Breastfed infants
• Older adults
• People with limited sun exposure
• Individuals with darker skin
• People with certain medical conditions affecting nutrient absorption

How often should vitamin D levels be checked? For most healthy individuals, routine screening for vitamin D deficiency is not recommended. However, if you’re at risk for deficiency or have symptoms that might be related to low vitamin D levels, your healthcare provider may recommend a blood test. The frequency of testing can vary based on individual risk factors and previous test results.

Vitamin D Deficiency: Risks and Prevention

Vitamin D deficiency can have significant health implications, affecting not only bone health but potentially contributing to a range of other health issues. Understanding the risks associated with deficiency and how to prevent it is crucial for maintaining overall well-being.

Consequences of Vitamin D Deficiency

• Rickets in children
• Osteomalacia in adults
• Increased risk of osteoporosis
• Muscle weakness
• Increased risk of falls, especially in older adults
• Potential links to various chronic diseases

How does vitamin D deficiency affect bone health? In children, severe vitamin D deficiency can lead to rickets, a condition characterized by softening and weakening of bones. In adults, deficiency can result in osteomalacia, which causes bone pain and muscle weakness. Both conditions occur because the body cannot effectively mineralize bone tissue without adequate vitamin D.

Beyond bone health, emerging research suggests potential links between vitamin D deficiency and various chronic conditions, including cardiovascular disease, certain cancers, and autoimmune disorders. However, more research is needed to fully understand these relationships and determine whether vitamin D supplementation can help prevent or manage these conditions.

Preventing Vitamin D Deficiency

To maintain adequate vitamin D levels and prevent deficiency, consider the following strategies:

1. Consume vitamin D-rich foods regularly
2. Get safe sun exposure
3. Consider vitamin D supplements if at risk for deficiency
4. Have your vitamin D levels checked if you’re in a high-risk group
5. Maintain a healthy lifestyle that supports overall nutrient absorption

Can vitamin D deficiency be reversed? In most cases, vitamin D deficiency can be effectively treated with a combination of dietary changes, safe sun exposure, and supplementation under medical supervision. The duration and intensity of treatment depend on the severity of the deficiency and individual health factors.

It’s important to note that while vitamin D is crucial for health, excessive intake can also be harmful. Vitamin D toxicity, although rare, can occur from extremely high doses of supplements over time. Always follow recommended dosages and consult with a healthcare provider before starting high-dose supplementation.

In conclusion, vitamin D plays a vital role in maintaining overall health, particularly in supporting bone strength, muscle function, and immune system health. By understanding the sources of vitamin D, recommended intake levels, and the factors that affect its absorption and production in the body, you can take proactive steps to ensure you’re getting enough of this essential nutrient. Whether through diet, safe sun exposure, or appropriate supplementation, maintaining adequate vitamin D levels is an important aspect of a healthy lifestyle.

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What is vitamin D and what does it do?

Vitamin D is a nutrient you need for good health. It helps your body absorb calcium, one of the main building blocks for strong bones. Together with calcium, vitamin D helps protect you from developing osteoporosis, a disease that thins and weakens the bones and makes them more likely to break. Your body needs vitamin D for other functions too. Your muscles need it to move, and your nerves need it to carry messages between your brain and your body. Your immune system needs vitamin D to fight off invading bacteria and viruses.

How much vitamin D do I need?

The amount of vitamin D you need each day depends on your age. Average daily recommended amounts are listed below in micrograms (mcg) and International Units (IU):

What foods provide vitamin D?

Very few foods naturally contain vitamin D. Fortified foods provide most of the vitamin D in the diets of people in the United States. Check the Nutrition Facts label for the amount of vitamin D in a food or beverage.

• Almost all of the U.S. milk supply is fortified with about 3 mcg (120 IU) vitamin D per cup. Many plant-based alternatives such as soy milk, almond milk, and oat milk are similarly fortified. But foods made from milk, like cheese and ice cream, are usually not fortified.
• Vitamin D is added to many breakfast cereals and to some brands of orange juice, yogurt, margarine, and other food products.
• Fatty fish (like trout, salmon, tuna, and mackerel) and fish liver oils are among the best natural sources of vitamin D.
• Beef liver, egg yolks, and cheese have small amounts of vitamin D.
• Mushrooms provide a little vitamin D. Some mushrooms have been exposed to ultraviolet light to increase their vitamin D content.

Can I get vitamin D from the sun?

Your body makes vitamin D when your bare skin is exposed to the sun. Most people get at least some vitamin D this way. However, clouds, smog, old age, and having dark-colored skin reduce the amount of vitamin D your skin makes. Also, your skin does not make vitamin D from sunlight through a window.

Ultraviolet radiation from sunshine can cause skin cancer, so it’s important to limit how much time you spend in the sun. Although sunscreen limits vitamin D production, health experts recommend using sunscreen with a sun protection factor (SPF) of 15 or more when you’re out in the sun for more than a few minutes.

What kinds of vitamin D dietary supplements are available?

Vitamin D is found in multivitamin/multimineral supplements. It is also available in dietary supplements containing only vitamin D or vitamin D combined with a few other nutrients. The two forms of vitamin D in supplements are D2 (ergocalciferol) and D3 (cholecalciferol). Both forms increase vitamin D in your blood, but D3 might raise it higher and for longer than D2. Because vitamin D is fat-soluble, it is best absorbed when taken with a meal or snack that includes some fat.

Am I getting enough vitamin D?

Because you get vitamin D from food, sunshine, and dietary supplements, one way to know if you’re getting enough is a blood test that measures the amount of vitamin D in your blood. In the blood, a form of vitamin D known as 25-hydroxyvitamin D is measured in either nanomoles per liter (nmol/L) or nanograms per milliliter (ng/mL). One nmol/L is equal to 0.4 ng/mL. So, for example, 50 nmol/L is the same as 20 ng/mL.

• Levels of 50 nmol/L (20 ng/mL) or above are adequate for most people for bone and overall health.
• Levels below 30 nmol/L (12 ng/mL) are too low and might weaken your bones and affect your health.
• Levels above 125 nmol/L (50 ng/mL) are too high and might cause health problems.

In the United States, most people have adequate blood levels of vitamin D. However, almost one out of four people have vitamin D blood levels that are too low or inadequate for bone and overall health.

Some people are more likely than others to have trouble getting enough vitamin D:

• Breastfed infants. Breast milk alone does not provide infants with an adequate amount of vitamin D. Breastfed infants should be given a supplement of 10 mcg (400 IU) of vitamin D each day.
• Older adults. As you age, your skin’s ability to make vitamin D when exposed to sunlight declines.
• People who seldom expose their skin to sunshine because they do not go outside or because they keep their body and head covered. Sunscreen also limits the amount of vitamin D your skin produces.
• People with dark skin. The darker your skin, the less vitamin D you make from sunlight exposure.
• People with conditions that limit fat absorption, such as Crohn’s disease, celiac disease, or ulcerative colitis. This is because the vitamin D you consume is absorbed in the gut along with fat, so if your body has trouble absorbing fat, it will also have trouble absorbing vitamin D.
• People with obesity or who have undergone gastric bypass surgery. They may need more vitamin D than other people.

What happens if I don’t get enough vitamin D?

In children, vitamin D deficiency causes rickets, a disease in which the bones become soft, weak, deformed, and painful. In teens and adults, vitamin D deficiency causes osteomalacia, a disorder that causes bone pain and muscle weakness.

What are some effects of vitamin D on health?

Scientists are studying vitamin D to better understand how it affects health. Here are several examples of what this research has shown:

Bone health and osteoporosis

Long-term shortages of vitamin D and calcium cause your bones to become fragile and break more easily. This condition is called osteoporosis. Millions of older women and men have osteoporosis or are at risk of developing this condition. Muscles are also important for healthy bones because they help maintain balance and prevent falls. A shortage of vitamin D may lead to weak, painful muscles.

Getting recommended amounts of vitamin D and calcium from foods (and supplements, if needed) will help maintain healthy bones and prevent osteoporosis. Taking vitamin D and calcium supplements slightly increases bone strength in older adults, but it’s not clear whether they reduce the risk of falling or breaking a bone.

Cancer

Vitamin D does not seem to reduce the risk of developing cancer of the breast, colon, rectum, or lung. It is not clear whether vitamin D affects the risk of prostate cancer or chance of surviving this cancer. Very high blood levels of vitamin D may even increase the risk of pancreatic cancer.

Clinical trials suggest that while vitamin D supplements (with or without calcium) may not affect your risk of getting cancer, they might slightly reduce your risk of dying from this disease. More research is needed to better understand the role that vitamin D plays in cancer prevention and cancer-related death.

Heart disease

Vitamin D is important for a healthy heart and blood vessels and for normal blood pressure. Some studies show that vitamin D supplements might help reduce blood cholesterol levels and high blood pressure—two of the main risk factors for heart disease. Other studies show no benefits. If you are overweight or have obesity, taking vitamin D at doses above 20 mcg (800 IU) per day plus calcium might actually raise your blood pressure. Overall, clinical trials find that vitamin D supplements do not reduce the risk of developing heart disease or dying from it, even if you have low blood levels of the vitamin.

Depression

Vitamin D is needed for your brain to function properly. Some studies have found links between low blood levels of vitamin D and an increased risk of depression. However, clinical trials show that taking vitamin D supplements does not prevent or ease symptoms of depression.

Multiple sclerosis

People who live near the equator have more sun exposure and higher vitamin D levels. They also rarely develop multiple sclerosis (MS), a disease that affects the nerves that carry messages from the brain to the rest of the body. Many studies find a link between low blood vitamin D levels and the risk of developing MS. However, scientists have not actually studied whether vitamin D supplements can prevent MS. In people who have MS, clinical trials show that taking vitamin D supplements does not keep symptoms from getting worse or coming back.

Type 2 diabetes

Vitamin D helps your body regulate blood sugar levels. However, clinical trials in people with and without diabetes show that supplemental vitamin D does not improve blood sugar levels, insulin resistance, or hemoglobin A1c levels (the average level of blood sugar over the past 3 months). Other studies show that vitamin D supplements don’t stop most people with prediabetes from developing diabetes.

Weight loss

Taking vitamin D supplements or eating foods that are rich in vitamin D does not help you lose weight.

Can vitamin D be harmful?

Yes, getting too much vitamin D can be harmful. Very high levels of vitamin D in your blood (greater than 375 nmol/L or 150 ng/mL) can cause nausea, vomiting, muscle weakness, confusion, pain, loss of appetite, dehydration, excessive urination and thirst, and kidney stones. Extremely high levels of vitamin D can cause kidney failure, irregular heartbeat, and even death. High levels of vitamin D are almost always caused by consuming excessive amounts of vitamin D from dietary supplements. You cannot get too much vitamin D from sunshine because your skin limits the amount of vitamin D it makes.

The daily upper limits for vitamin D include intakes from all sources—food, beverages, and supplements—and are listed below in micrograms (mcg) and international units (IU). However, your health care provider might recommend doses above these upper limits for a period of time to treat a vitamin D deficiency.

Does vitamin D interact with medications or other dietary supplements?

Yes, vitamin D supplements may interact with some medicines. Here are several examples:

• Orlistat (Xenical® and alli®) is a weight-loss drug. It can reduce the amount of vitamin D your body absorbs from food and supplements.
• Cholesterol-lowering statins might not work as well if you take high-dose vitamin D supplements. This includes atorvastatin (Lipitor®), lovastatin (Altoprev® and Mevacor®), and simvastatin (FloLipid™ and Zocor®)
• Steroids such as prednisone (Deltasone®, Rayos®, and Sterapred®) can lower your blood levels of vitamin D.
• Thiazide diuretics (such as Hygroton®, Lozol®, and Microzide®) could raise your blood calcium level too high if you take vitamin D supplements.

Tell your doctor, pharmacist, and other health care providers about any dietary supplements and prescription or over-the-counter medicines you take. They can tell you if the dietary supplements might interact with your medicines. They can also explain whether the medicines you take might interfere with how your body absorbs or uses other nutrients.

Vitamin D and healthful eating

People should get most of their nutrients from food and beverages, according to the federal government’s Dietary Guidelines for Americans. Foods contain vitamins, minerals, dietary fiber, and other components that benefit health. In some cases, fortified foods and dietary supplements are useful when it is not possible otherwise to meet needs for one or more nutrients (for example, during specific life stages such as pregnancy). For more information about building a healthy dietary pattern, see the Dietary Guidelines for Americans and the U.S. Department of Agriculture’s MyPlate.

Where can I find out more about vitamin D?

• For more information on vitamin D:
  • Office of Dietary Supplements, Health Professional Fact Sheet on Vitamin D
  • MedlinePlus®, Vitamin D

• For more information on food sources of vitamin D:
  • Office of Dietary Supplements, Health Professional Fact Sheet on Vitamin D
  • U. S. Department of Agriculture (USDA), FoodData Central
  • Nutrient List for vitamin D (listed by food or by vitamin D content), USDA

• For more advice on choosing dietary supplements:
  • Office of Dietary Supplements, Frequently Asked Questions: Which brand(s) of dietary supplements should I purchase?

• For information about building a healthy dietary pattern:
  • Dietary Guidelines for Americans
  • MyPlate

Disclaimer

This fact sheet by the National Institutes of Health (NIH) Office of Dietary Supplements (ODS) provides information that should not take the place of medical advice. We encourage you to talk to your health care providers (doctor, registered dietitian, pharmacist, etc.) about your interest in, questions about, or use of dietary supplements and what may be best for your overall health. Any mention in this publication of a specific product or service, or recommendation from an organization or professional society, does not represent an endorsement by ODS of that product, service, or expert advice.

Updated:
November 8, 2022
History of changes to this fact sheet

Benefits, deficiency, sources, and dosage

Vitamin D is essential for bone strength and may support the immune system and other functions. The human body produces vitamin D as a response to sun exposure. A person can also boost their vitamin D intake through certain foods or supplements.

Vitamin D is essential for maintaining healthy bones and teeth. It also plays many other important roles in the body, including regulating inflammation and immune function.

Despite its name, vitamin D is not a vitamin but a hormone or prohormone.

In this article, we look at the benefits of vitamin D, what happens to the body when people do not get enough, and how to boost vitamin D intake.

Vitamin D plays a critical role in many bodily functions.

Healthy bones

Vitamin D promotes intestinal calcium absorption and helps maintain adequate blood levels of calcium and phosphorus, which is necessary for healthy bone mineralization.

Vitamin D deficiency in children can cause rickets, leading to a bowlegged appearance due to the softening of the bones. Similarly, in adults, vitamin D deficiency manifests as osteomalacia or a softening of the bones. Osteomalacia results in poor bone density and muscular weakness.

Long-term vitamin D deficiency can also present as osteoporosis.

Immune function

An adequate intake of vitamin D may support good immune function and reduce the risk of autoimmune diseases.

Researchers suggest that vitamin D plays an important role in immune function. They believe there may be a link between long-term vitamin D deficiency and the development of autoimmune conditions, such as diabetes, asthma, and rheumatoid arthritis, but more research is necessary to confirm the link.

While test-tube studies have shown vitamin D to have a positive effect on the immune response of human cells, researchers are yet to replicate these findings in controlled human trials.

Although the body can create vitamin D, some people are more likely to be at risk of a deficiency than others. Factors that can influence this include:

• Skin color: Pigmentation in the skin reduces the body’s ability to absorb ultraviolet B (UVB) rays from the sun. Absorbing sunlight is essential for the skin to produce vitamin D.
• Lack of sun exposure: People who live in northern latitudes or areas of high pollution, work night shifts, or are homebound should aim to consume vitamin D from food sources whenever possible.
• Breastfeeding: The American Academy of Pediatrics recommends that all breastfed infants receive 400 international units (IU) per day of oral vitamin D.
• Older adults: The skin’s ability to synthesize vitamin D decreases with age. Older adults may also spend more time indoors.
• Those with conditions that limit fat absorption: Vitamin D is fat-soluble, meaning intake is dependent on the gut absorbing dietary fats. Conditions that limit fat absorption can decrease vitamin D intake from the diet.
• People with obesity: High levels of body fat can limit the body’s ability to absorb vitamin D from the skin.
• People following a gastric bypass: This surgery bypasses a part of the upper intestine that absorbs large amounts of vitamin D. This bypass can cause a deficiency.

Read more on vitamin D deficiency.

The majority of people with a vitamin D deficiency do not present with symptoms. However, a chronic deficiency may cause hypocalcemia, a calcium deficiency disease, and hyperparathyroidism, where the parathyroid glands create a hormone imbalance that raises the blood calcium levels.

These conditions can lead to secondary symptoms including:

• bone fragility, especially in older adults
• osteoporosis
• bone pain
• fatigue
• muscle twitching
• muscle weakness
• myalgias, or muscle pain
• arthralgias, or joint stiffness

If Vitamin D deficiency continues for long periods, it may result in complications, such as:

• cardiovascular conditions
• autoimmune problems
• neurological diseases
• infections
• pregnancy complications
• certain cancers, including breast, prostate, and colon

Infancy and childhood is a period of rapid growth bone growth. Due to this, it is essential for infants to get adequate amounts of vitamin D.

Chronic vitamin D deficiency can cause rickets, which is a softening of bone tissues that can lead to the malformation of bones and joints.

Vitamin D deficiency also has links to high blood pressure and hypertension in children. A 2018 study found a possible connection between low vitamin D levels and arterial wall stiffness in children.

The American Academy of Allergy Asthma and Immunology (AAAAI) suggests a connection between low vitamin D exposure and an increased risk of allergic sensitization.

For example, children who live closer to the equator have lower rates of admission to the hospital for allergies and fewer prescriptions for epinephrine auto-injectors, or EpiPens. They are also less likely to have a peanut allergy.

A 2019 review suggests that pregnant people deficient in vitamin D may have a greater risk of developing preeclampsia and giving birth preterm.

Researchers of a 2020 review study found that there may be an association between higher vitamin D concentrations during pregnancy and a decreased risk of preeclampsia and premature birth. However, researchers need well-designed clinical trials with vitamin D supplementation in order to better define associations.

Some research associates a poor vitamin D status with gestational diabetes. Treating vitamin D deficiency may also reduce the risk of asymptomatic bacterial vaginosis in pregnant people. However, conflicting research found no links between vitamin D supplementation and the prevention of bacterial vaginosis.

There may be an association between adequate vitamin D intake during pregnancy and a reduced risk of asthma and food allergy development in the resulting newborns. However, the evidence is not definitive, and more studies are necessary.

For more in-depth resources about vitamins, minerals, and supplements, visit our dedicated hub.

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People can often get the majority of their vitamin D intake from sunlight exposure. However, people at risk of developing vitamin D deficiency, and many other people, cannot solely rely on sunlight exposure for vitamin D production. During the winter months, when the sun is not as strong, everyone can benefit from vitamin D supplements.

The following foods are a source of vitamin D:

• fatty fish, such as salmon, mackerel, and tuna
• egg yolks
• cheese
• beef liver
• mushrooms
• fortified milk
• fortified cereals and juices

People can measure vitamin D intake in micrograms (mcg) or international units (IU). One mcg of vitamin D is equal to 40 IU.

The recommended daily intakes of vitamin D are as follows:

Learn how to get more vitamin D from the sun here.

The upper limit that healthcare professionals recommend for vitamin D is 4,000 IU per day for an adult. However, the National Institutes of Health (NIH) reports that vitamin D toxicity is unlikely at intakes under 10,000 IU per day.

Vitamin D toxicity is typically the result of inappropriate supplement dosing and prescription errors.

Excessive vitamin D consumption can lead to hypercalcemia, or an excessively high blood calcium level. This can lead to calcification of bones and the hardening of blood vessels, kidneys, lungs, and heart tissues.

Hypercalcemia can be life threatening and requires immediate medical attention.

The most common symptoms of excessive vitamin D include headaches and nausea. However, too much vitamin D can also lead to the following:

• loss of appetite
• dry mouth
• a metallic taste
• vomiting
• constipation
• diarrhea

Excessive vitamin D usually occurs from accidental overconsumption and prescription errors.

If someone is taking supplements, they should choose their brand carefully, as the Food and Drug Administration (FDA) does not monitor the safety or purity of supplements the same way it does pharmaceuticals.

A complete diet and regular eating pattern are most important in disease prevention and good health. It is better to eat a diet with various nutrients than to concentrate on only a few nutrients.

The body produces vitamin D due to sun exposure. Many foods and supplements also contain vitamin D. The vitamin plays an important role in maintaining bones, teeth, and optimal immune function.

A vitamin D deficiency can cause calcium deficiency disease, and hyperparathyroidism, a hormone imbalance that raises the blood calcium levels.

Why vitamin D deficiency is dangerous and how to diagnose it

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WHAT IS VITAMIN D DEFICIENCY DANGEROUS AND HOW TO DIAGNOSIS IT

“For most people, vitamin D is linked to the bones—it was given to children as fish oil to prevent rickets, and television ads recommend it to the elderly to protect them from osteoporosis. It turns out that he is valuable, not only for this”

Alexander Melnikov, “Arguments and Facts”

What is vitamin D?

Vitamin D regulates the absorption of calcium and phosphorus minerals, their blood levels and their entry into bone tissue and teeth. Together with vitamin A and calcium or phosphorus, it protects the body from colds, diabetes, eye and skin diseases. It also helps prevent dental caries and gum disease, helps fight osteoporosis, and speeds up the healing of fractures.

Vitamin D determination is used to: Diagnose calcium metabolism disorders (rickets, pregnancy, malnutrition and digestion, hyperparathyroidism, osteoporosis).

Vitamin D analysis is performed to diagnose hypo- and beriberi, as well as a number of chronic diseases associated with a lack of this substance in the body. The procedure belongs to general clinical trials.

Why is it important to test for vitamin D?

Vitamin D maintains the level of inorganic phosphorus in the blood, prevents muscle weakness, increases the body’s immunity, affects the cells of the intestines, kidneys and muscles, and is involved in the regulation of blood pressure and heart function.

Vitamin D is essential for the functioning of the thyroid gland and normal blood clotting.

Vitamin D affects the absorption of calcium and magnesium, kidney function, susceptibility to skin diseases and heart disease.

Vitamin D blocks the uncontrolled reproduction of body cells, which makes it effective in the prevention of oncological diseases (cancer of the breast, prostate, colon, pancreas, esophagus, ovaries, uterus, stomach and a number of other tumors).

Main symptoms of vitamin D deficiency/overdose

Vitamin D overdose causes the following symptoms:

• weakness
• loss of appetite
• nausea
• locks
• diarrhea
• sharp pains in the joints
• headaches and muscle pains
• fever
• increased blood pressure
• convulsions
• slow pulse
• shortness of breath
• development of osteoporosis
• bone tissue demineralization
• deposition of calcium salts in organs, impeding their functions

Symptoms of vitamin D deficiency

In the early stages, vitamin D deficiency manifests itself in the form of the following symptoms:

• loss of appetite
• insomnia
• burning in the mouth and throat
• weight loss
• blurred vision

Further development of osteoporosis is observed. And in children it is rickets, spinal deformities, growth and developmental delay.

How do I get tested for vitamin D?

Vitamin D tests are performed both on doctor’s orders and at the client’s own request. Blood serum serves as a material for laboratory diagnostics. In order to take a blood test, the patient does not require special preparation.

Preparation for the examination

The examination is carried out in the morning, strictly on an empty stomach, i.e. at least 8 hours should elapse between the last meal (preferably at least 12 hours). The day before blood donation, it is necessary to limit the intake of fatty foods, alcohol. Immediately before donating blood, you must refrain from smoking, do not drink juice, tea, coffee (especially with sugar), you can drink water.

• Swiss cheese
• Beef liver
• Beef
• Egg
• Pork
• Milk
• Sardines
• Salmon
• Cod liver oil

The turnaround time for a vitamin D test is 1 day. For more information contact tel. +7 (342) 215-00-68

We recommend that you monitor your health and contact a specialist when the first symptoms are detected, without postponing a visit to the doctor for a long time!

Vitamin D – the importance and its role

Vitamin D – the importance and its role

“What is vitamin D? What do we know about him? In the modern philistine view, this is the substance that children need so that there is no rickets – a severe disorder of calcium-phosphorus metabolism. Is it only this, really important, role that the solar vitamin plays?

Biochemistry of Vitamin D

Where vitamin D is synthesized, what stages of metabolism it goes through. It is known that in the southern regions, where there are more sunny days, people get more vitamin D than in northern countries. Since under the action of sunlight, namely the UV-B spectrum with a wavelength of 290-315 nm, a very valuable vitamin is synthesized in the skin, which protects against the pathology of the bone and muscle systems.

Cholecalciferol (Vitamin D3) is synthesized in the skin from a substrate called 7-dehydrocholesterol (the so-called cholesterol). This form of the vitamin then binds to a carrier protein and enters the bloodstream (see figure above). In addition, a certain amount of vitamin D comes from food. Further, in the liver, cholecalciferol is converted by hydroxylation into the active metabolite 25-hydroxyvitamin D3, which is designated as 25 (OH) D3 or another name – calcidiol. The next step, with the blood flow, this form of the vitamin enters the kidneys, where it undergoes another hydroxylation reaction and as a result a metabolite is formed with the complex name 1,25-dioxycholecalciferol or 1,25 (OH) 2D3 or calcitriol

This is the most active and most unstable form of vitamin D. It is due to this metabolite that all its biological effects are realized. Calcitriol binds to its carrier protein (VDBP) and spreads throughout the body to perform its important functions

Biological effects of vitamin D

Effects on genes

Almost every cell in our body has on its surface a special docking site for vitamin D – it is the VDR receptor. The receptor has two domains that bind to the vitamin and cell DNA. The uniqueness of vitamin D is that, through its receptor, it immediately acts on cellular DNA, giving a signal for the implementation (expression) of a particular gene. This is especially true for skin tissues, large intestine and adrenal cortex. There are special sections on DNA that react to the presence or absence of this important substance. They were called vitamin D-binding elements (VDRE). When the active metabolite CALCITRIOL, which is 100 times more active than calcidiol, binds to its own VDR receptor, this receptor immediately connects to nuclear DNA, namely to individual DNA regions (VDRE). And the processes that are programmed in a certain gene are launched, for example, the synthesis of a specific protein for some system, for example, the immune system. Vitamin D influences the levels of other hormones, growth and inflammation factors, numerous proteins, and, of course, blood calcium levels. It has been established and proven that vitamin D controls more than 200 genes, but it is also believed that this number is really up to 5000 genes. By the way, only 7-10% of the genes of the total number of genes controlled by Vit D are involved in the regulation of calcium in the blood. Thus, since the spectrum of action of vitamin D is much wider and larger.

It is because of its mechanism that vitamin D is now considered not a vitamin at all, but a real hormone. Only hormones have the ability to influence how DNA works! And it has recently become known that this substance can have an epigenetic effect. The prefix “epi” means “above”, that is, supragenetic influence. In other words, vitamin D can change the information recorded in our genes, that is, affect the genes by changing them.

But vitamin-hormone D also has non-genomic mechanisms of action on the cell. As a rule, this is the control of the work of various enzymes in the cell matrix (adenylate cyclase, phospholipase, protein kinase, and others), the effect on mitochondria, and therefore active participation in the energy supply of cells.

What Vitamin D controls

– Calcium regulation, namely intestinal absorption and bone remodeling. With a deficiency, rickets, osteoporosis, osteomalacia develop.

-Regulation of the cell cycle, i.e. so that the cell grows, develops and dies in time. With a deficiency, the risks of many types of malignant oncological diseases increase, especially cancer of the prostate, breast, colon and rectum, and leukemia.

– Influence on the immune system, namely on the work of macrophages and the synthesis of antimicrobial peptides. Lack leads to frequent infectious diseases, up to tuberculosis, as well as autoimmune disorders (type 1 diabetes mellitus, autoimmune thyroiditis, multiple sclerosis, psoriasis, ulcerative colitis and Crohn’s disease, and others)

– Participates in the synthesis of insulin. Vitamin D deficiency leads to impaired insulin secretion, glucose tolerance and diabetes mellitus.

– Regulation of cardiovascular diseases. If the vitamin is not enough, then high-renin (renal) hypertension develops, increased thrombus formation, the risks of heart disease, myocardial infarction in particular, increase.

– Controls the muscular system. Deficiency leads to various myopathies.

-Affects the functioning of the brain. With a lack of vitamin during fetal development, the risk of behavioral disorders in adulthood is high, and in adults the risk of Parkinson’s disease and mental degradation increases.

– Participates in regeneration (wound healing, regulation of inflammation processes).

These effects are just a few of the many effects vitamin D has on the human body.

Who needs to be tested for vitamin D

It is necessary to look at the indicator for each person, regardless of age and gender, and regardless of the degree of health. People with chronic diseases should do this analysis without fail, as well as all frequently ill adults and children.

Explanation of tests 25 (OH) D

So, you passed the test and got the result. Let’s see what your scores mean.

< 10 ng/ml severe deficiency

< 20 ng/ml deficiency

20-30 ng/ml deficiency

30-100 ng/ml adequate

> 150 ng / ml – possible toxic effect

Note adequate levels of 30 to 100 ng/ml. Very wide range. What numbers should be followed? A minimum rate of 30 ng / ml will ensure the prevention of rickets or lesions of the skeletal system. And if you want a systemic effect, effective prevention of cancer and immune disorders, then the indicator should be almost 3 times higher. Today, scientists recommend sticking to a vitamin D indicator of at least 80 ng / ml. It is these numbers that provide the full effects of the D-hormone. The rule is valid for both children and adults. However, reaching levels of 50 ng/mL already reduces risks:

– rickets by 100%

– osteomalacia by 100%

– cancer in general by 75%

– breast cancer by 50%

– cancer ovaries by 25%

– kidney cancer by 67%

– Endometrial cancer by 36%

Type 1 diabetes by 80%

– Type 2 diabetes by 50%

– Fractures by 50%

– Falls by 72% 9 0003

– 50% multiple sclerosis

– myocardial infarction by 50%

– vascular disease by 80%

– pre-eclampsia of pregnant women by 50%

– caesarean section by 75% To to replenish and maintain vitamin D levels, there are several ways:

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2. consumption of foods rich in vitamin D2 and D3 (oily sea fish, cod liver, seafood, eggs, cottage cheese and butter, chicken and beef)

3. additional intake of dietary supplements containing vitamin D in various forms

However, a person cannot stay in the sun indefinitely, as well as eat such an amount of food containing vitamin D that adequately compensates for the deficiency. Therefore, an additional intake of cholecalciferol in the form of a medicinal substance is recommended

This form is the most common and popular, both for the prevention of deficiency conditions and for the treatment of diseases caused by this deficiency. In the pharmacy, you can meet two types of medicines: an aqueous solution and an oil solution. A prolonged form of vitamin D has also appeared on the market.

The standard recommendation for vitamin D is 400 IU/day. But if you have a very low blood count, then this dose will not normalize your vitamin D levels. Since now every second person has a deficiency and deficiency, these recommendations are no longer relevant and they have been replaced by new doses, which are many times larger, and which will quickly bring your vitamin D level back to normal, and after it your well-being.