How does vitamin D help with calcium absorption. What are the main sources of vitamin D. Can you get too much vitamin D. Should everyone get their vitamin D levels checked. What are the consequences of vitamin D deficiency.

The Crucial Role of Vitamin D in Calcium Absorption

Vitamin D plays a vital role in our body’s ability to absorb and utilize calcium. This essential nutrient acts as a key that unlocks the door for calcium to enter our bloodstream from the intestines. Without adequate vitamin D, our bodies struggle to maintain proper calcium levels, which can lead to various health issues.

How exactly does vitamin D facilitate calcium absorption? The process involves several steps:

1. Vitamin D is converted to its active form, calcitriol, in the liver and kidneys.
2. Calcitriol increases the efficiency of calcium absorption in the small intestine.
3. It also helps regulate calcium levels in the blood by promoting calcium reabsorption in the kidneys.
4. Vitamin D stimulates the production of calcium-binding proteins that aid in calcium transport.

This intricate relationship between vitamin D and calcium is crucial for maintaining strong bones and teeth throughout our lives. Dr. Karl Insogna, director of Yale Medicine’s Bone Center, emphasizes the importance of this relationship, stating that “not getting enough Vitamin D can have serious consequences, including increased rates of bone loss or even osteomalacia (‘soft bones’) in adults and rickets (a deforming bone disorder) in children.”

Sources of Vitamin D: Sun, Food, and Supplements

There are three primary ways to obtain vitamin D: sunlight exposure, dietary sources, and supplements. Each method has its advantages and considerations.

Sunlight: The Natural Vitamin D Factory

Our skin has a remarkable ability to produce vitamin D when exposed to sunlight. Dr. David J. Leffell, chief of Dermatologic Surgery at Yale Medicine, explains, “We each have vitamin D receptor cells that, through a chain of reactions starting with conversion of cholesterol in the skin, produce vitamin D3 when they’re exposed to ultraviolet B (UVB) from the sun.”

Is sunlight-generated vitamin D superior to other sources? Contrary to popular belief, Dr. Insogna clarifies that “it doesn’t matter if you’re getting D2 or D3, and the sunlight-generated kind isn’t better than the nutritional variety. The body can use each perfectly fine.”

Dietary Sources: Natural and Fortified

While some foods naturally contain vitamin D, their concentrations are often insufficient to meet our daily requirements. Natural sources include:

• Fatty fish (salmon, tuna, mackerel)
• Beef liver
• Egg yolks

To address this nutritional gap, many common foods are fortified with vitamin D, including:

• Milk
• Cereal
• Some orange juices

This fortification practice dates back to the 1930s when manufacturers began voluntarily enriching these foods to reduce the incidence of nutritional rickets.

Supplements: A Reliable Alternative

Vitamin D supplements are available in both pill and liquid form. They are particularly beneficial for individuals with:

• Fat absorption issues
• Lactose intolerance
• Milk allergies
• Darker skin tones
• Medical conditions limiting sun exposure

When choosing supplements, it’s crucial to adhere to the recommended daily allowance (RDA) for your age group. For most healthy adults, this is 600 IU per day, increasing to 800 IU for those over 70.

The Vitamin D Myth: More Is Not Always Better

A common misconception is that increasing vitamin D intake will always lead to better health outcomes. However, this belief can be dangerous. Dr. Thomas Carpenter, a pediatric endocrinologist at Yale Medicine, strongly cautions against this notion, stating, “Absolutely not. That’s a misconception.”

Why is excessive vitamin D intake problematic? The fat-soluble nature of vitamin D means it’s stored in our body’s fat cells. When these storage sites become saturated, excess vitamin D enters the bloodstream, potentially leading to hypercalcemia (elevated blood calcium levels).

Dr. Carpenter shares a cautionary tale: “Just recently, I treated an infant whose blood vitamin D level was in the hundreds when it should have been between 20 and 50 nanograms/milliliter (ng/mL). The child, who developed high blood calcium (hypercalcemia), had to be hospitalized and treated with several types of medications to get the calcium levels down to normal levels.”

This case highlights the importance of adhering to recommended dosages and consulting healthcare professionals before starting any supplement regimen.

Vitamin D Testing: Necessary or Overrated?

With the increasing awareness of vitamin D’s importance, many wonder if they should have their levels checked regularly. Dr. Karl Insogna provides a straightforward answer: “Generally, no.”

While vitamin D testing can be valuable for certain at-risk populations, routine testing for the general population is not recommended. Factors that might warrant vitamin D testing include:

• Osteoporosis or other bone health concerns
• Malabsorption disorders (e.g., celiac disease, Crohn’s disease)
• Certain medications that affect vitamin D metabolism
• Chronic kidney or liver disease

For most healthy individuals following a balanced diet and maintaining regular sun exposure, vitamin D levels are likely to be within an acceptable range.

The Consequences of Vitamin D Deficiency

While excessive vitamin D intake can be harmful, deficiency also poses significant health risks. Understanding these consequences underscores the importance of maintaining adequate vitamin D levels.

Bone Health Implications

Vitamin D deficiency can lead to:

• Osteomalacia (softening of bones) in adults
• Rickets in children
• Increased risk of fractures
• Reduced bone density

These conditions arise from the body’s inability to properly mineralize bone tissue due to insufficient calcium absorption.

Beyond Bone Health

Emerging research suggests that vitamin D deficiency may be associated with:

• Increased risk of certain cancers
• Autoimmune disorders
• Cardiovascular disease
• Depression

While more studies are needed to fully understand these relationships, maintaining adequate vitamin D levels appears to have far-reaching health benefits.

Optimizing Vitamin D Intake: A Balanced Approach

Given the potential risks of both deficiency and excess, how can one optimize their vitamin D intake? The key lies in a balanced approach that considers individual factors and follows expert recommendations.

Tailoring Intake to Age and Health Status

The recommended daily allowance (RDA) for vitamin D varies by age:

• Infants (0-12 months): 400 IU
• Children and adults up to age 70: 600 IU
• Adults over 70: 800 IU

These guidelines provide a general framework, but individual needs may vary based on factors such as skin tone, geographical location, and underlying health conditions.

Combining Sources for Optimal Intake

Rather than relying solely on one source of vitamin D, a combined approach often yields the best results:

1. Incorporate vitamin D-rich foods into your diet
2. Enjoy safe sun exposure (10-30 minutes of midday sun several times per week)
3. Consider supplements if dietary intake and sun exposure are insufficient

This multi-faceted strategy helps ensure steady vitamin D levels while minimizing the risk of deficiency or excess.

The Future of Vitamin D Research

As our understanding of vitamin D’s role in human health continues to evolve, ongoing research promises to shed light on several key areas:

Personalized Vitamin D Recommendations

Future studies may help develop more tailored vitamin D guidelines based on individual genetic profiles, lifestyle factors, and health conditions. This personalized approach could optimize the benefits of vitamin D while minimizing risks.

Vitamin D and Immune Function

Recent interest in vitamin D’s potential role in supporting immune function has spurred new research directions. Scientists are investigating how vitamin D might influence the body’s response to various pathogens and autoimmune conditions.

Vitamin D and Mental Health

The relationship between vitamin D and mental health disorders, particularly depression, is an area of growing interest. Future research may clarify whether vitamin D supplementation could play a role in mental health treatment strategies.

As research progresses, our understanding of vitamin D’s complex role in human health will undoubtedly deepen, potentially leading to more refined recommendations and therapeutic applications.

Vitamin D Myths ‘D’-bunked > News > Yale Medicine

Doctors tell you what you need to know about vitamin D. What they have to say may surprise you.

You may have heard every vitamin D myth under the sun—so many, in fact, that you might be at the point of throwing your hands up in the air in frustration. Why can’t there be a simple answer? 

First, some facts: Your body needs vitamin D. Its main job is to help the body absorb calcium from the intestines. This calcium is necessary to help “mineralize the skeleton” over the course of your lifetime and is a critical mineral for forming the hardened bone that keeps you strong and healthy.

On the other hand, “not getting enough Vitamin D can have serious consequences, including increased rates of bone loss or even osteomalacia (‘soft bones’) in adults and rickets (a deforming bone disorder) in children,” says Yale Medicine endocrinologist Karl Insogna, MD, director of the Yale Medicine’s Bone Center.

How do you get vitamin D?

The short answer is from food, the sun or supplements.

There are two main kinds of vitamin D—vitamin D2 and vitamin D3—which you can get from (and occur naturally in) certain foods like salmon, tuna, mackerel and beef liver and egg yolks. But because we don’t consume large enough quantities of these foods, they can’t be our sole source of vitamin D. That’s why foods like milk, cereal and some orange juices are vitamin D2- and D3-fortified. (Since the 1930s, manufacturers have voluntarily enriched these foods with vitamin D to help reduce the incidence of nutritional rickets.)

When exposed to the sun, your skin can manufacture its own vitamin D. “We each have vitamin D receptor cells that, through a chain of reactions starting with conversion of cholesterol in the skin, produce vitamin D3 when they’re exposed to ultraviolet B (UVB) from the sun,” says Yale Medicine dermatologist David J. Leffell, MD, chief of Dermatologic Surgery.  

Another avenue to get vitamin D is by taking supplements. These come in both pill and liquid form. They are generally recommended for people with fat absorption issues, lactose intolerance, milk allergies, as well as for people with darker skin tones or with certain medical conditions that prevent them from going outdoors. 

How does the body process vitamin D?

After vitamin D is absorbed through the skin or acquired from food or supplements, it gets stored in the body’s fat cells. Here it remains inactive until it’s needed. Through a process called hydroxylation, the liver and kidneys turn the stored vitamin D into the active form the body needs (called calcitriol). In case you were wondering, it doesn’t matter if you’re getting D2 or D3, and the sunlight-generated kind isn’t better than the nutritional variety. “The body can use each perfectly fine,” says Dr. Insogna. 

Those are the basic facts, but some questions might remain: How should you get vitamin D? How much should you get and when should you worry about your levels? In light of these common questions, our Yale Medicine doctors help clear up some confusion about vitamin D, separating fact from fiction.

The more vitamin D you take, the better? Absolutely not.

—Thomas Carpenter, MD, Yale Medicine pediatric endocrinologist and director of the Yale School of Medicine’s Center for X-Linked Hypophosphatemia

That’s a misconception. Vitamin D is stored in fat. So, if you’re a small person and getting large doses, you have less available storage, which means vitamin D goes into your blood and you may absorb too much calcium, creating a toxic situation. And it’s unclear how long you have until you exceed the upper limits of vitamin D intake before it becomes dangerous. (Modest increases above the RDA are not likely to cause harm.)

Just recently, I treated an infant whose blood vitamin D level was in the hundreds when it should have been between 20 and 50 nanograms/milliliter (ng/mL). The child, who developed high blood calcium (hypercalcemia), had to be hospitalized and treated with several types of medications to get the calcium levels down to normal levels.   

You can now get 50,000 IU tablets over the counter. There are patients with specific issues who might need a prescription for high levels of vitamin D, but for most people, that amount will raise your vitamin D level too high.

When shopping for supplements, always look for ones that offer the daily recommended allowance (RDA) you need for your age bracket: For most healthy people, it’s 600 IU per day, but for people over age 70 who need a little more—it’s about 800 IU. That’s because, as people age (women after menopause, in particular), they less efficiently synthesize vitamin D and absorb calcium. Babies should be getting smaller amounts in their first year of life, between 200 and 400 IU.

Should everyone get their vitamin D levels checked? Generally, no.

—Karl Insogna, MD, director of Yale Medicine’s Bone Center

Most people should be fine. Testing is important only for certain populations: for people who are institutionalized; for patients with a gastrointestinal disorder (like inflammatory bowel disease) or osteoporosis; those who have had weight loss surgery; those on anti-convulsant medications; and children who are immobilized and not outside and active. If you’re over 70, I recommend getting your levels checked at least one time.

People whose cultural or religious beliefs require them to be fully clothed, especially if they’re living in northern climates, and whose dietary habits include little or no dairy (which is vitamin-D-fortified), may also be vitamin D-deficient and should be tested.

Is vitamin D deficiency an epidemic? No, it’s not.

—Thomas Carpenter, MD, Yale Medicine pediatric endocrinologist and director of the Yale School of Medicine’s Center for X-Linked Hypophosphatemia

Based on the United States Dietary Association (USDA) and National Health and Nutrition Surveys (and using 20ng/mL as the lower limit), the bulk of the population is not vitamin D-deficient. The population we tend to see vitamin D deficiency in—and it’s typically in wintertime—are breastfed infants. Breast milk doesn’t have much vitamin D in it. That’s what spurred a recommendation from the American Academy of Pediatrics that every breastfed infant be given vitamin D (if they’re being given liquid multivitamin drops, they’re getting enough of it). But if infants aren’t given multivitamin drops, they need to be given 200 IU a day of vitamin D for the first two months of life and 400 units a day afterwards until they’re drinking formula or milk, which are each fortified with vitamin D.

Is it best to get your vitamin D from the sun? Definitely not!

—David J. Leffell, MD, Yale Medicine dermatologist and chief of Dermatologic Surgery

One of the biggest challenges we’ve faced in dermatology and in the world of skin cancer prevention has been a lot of misinformation about vitamin D metabolism.

There are claims that one needs to get a certain amount of sun exposure every day in order to produce enough vitamin D to be healthy. It’s just not true. The majority of people can get their vitamin D from nutritional supplements and from vitamin D-fortified foods. 

There are some people (who are typically not dermatologists or experts in the biology of skin cancer) who have advocated for tanning to get vitamin D. But we know that UVB light causes skin cancer and that protecting yourself against it makes sense. As a doctor who treats patients who have melanomas, I want the general public to be advised that under no circumstances can use of a tanning bed or tanning in general be justified on the basis of vitamin D. Take a supplement instead.

The final verdict on vitamin D

No bones about it, the endocrinologists we interviewed agree with our dermatologist.

“Just being outdoors, you get a fair amount of sun exposure and some sun-related generation of vitamin D,” says Dr. Insogna. “Because skin cancer, particularly melanoma, can be such a devastating disease, it’s best to use sunblock when outdoors in strong sunlight for any prolonged length of time. Because this may limit the amount of vitamin D you get from sun exposure, make sure your diet includes sources of vitamin D from foods or supplements,” he says.

Both your skin and your bones will thank you.

Click here for more information about Yale Medicine’s Endocrinology Department. Or to make an appointment call 203-737-1932.

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Vitamin D and your health: Breaking old rules, raising new hopes

Vitamin D was discovered in 1920, culminating the long search for a way to cure rickets, a painful childhood bone disease. Within a decade, the fortification of foods with vitamin D was under way, and rickets became rare in the United States. But solving the problem of rickets was only the beginning of research into vitamin D. Research results suggest that vitamin D may have a role in  other aspects of human health.

Breaking the old rules

Vitamin D is one of the 13 vitamins discovered in the early 20th century by doctors studying nutritional deficiency diseases. Ever since, scientists have defined vitamins as organic (carbon-containing) chemicals that must be obtained from dietary sources because they are not produced by the body’s tissues. Vitamins play a crucial role in our body’s metabolism, but only tiny amounts are needed to fill that role.

Although vitamin D is firmly enshrined as one of the four fat-soluble vitamins, it is not technically a vitamin. True, it’s essential for health, and only minuscule amounts are required. But it breaks the other rules for vitamins because it’s produced in the human body, it’s absent from all natural foods except fish and egg yolks, and even when it’s obtained from foods, it must be transformed by the body before it can do any good.

As our habits change, most of us cannot rely on our bodies to produce vitamin D the old-fashioned way. Instead, we increasingly depend on artificially fortified foods and pills to provide this vital nutrient. Coming full circle in the modern world, this substance may actually come to fit the technical definition of a vitamin.

What is vitamin D?

Vitamin D is not one chemical but many. The natural type is produced in the skin from a universally present form of cholesterol, 7-dehydrocholesterol. Sunlight is the key: Its ultraviolet B (UVB) energy converts the precursor to vitamin D₃. In contrast, most dietary supplements are manufactured by exposing a plant sterol to ultraviolet energy, thus producing vitamin D₂. Because their function is almost identical, D₂ and D₃ are lumped together under the name vitamin D — but neither will function until the body works its magic (see figure).

The first stop is in the liver, where vitamin D picks up extra oxygen and hydrogen molecules to become 25-hydroxyvitamin D, or 25(OH)D. This is the chemical that doctors usually measure to diagnose vitamin D deficiencies. But although 25(OH)D is used for diagnosis, it can’t function until it travels to the kidney. There it acquires a final pair of oxygen and hydrogen molecules to become 1,25 dihydroxy vitamin D; scientists know this active form of the vitamin as 1,25(OH)₂D, or calcitriol, but for ordinary folks the name vitamin D is accurate enough.

How it works

Vitamin D’s best-known role is to keep bones healthy by increasing the intestinal absorption of calcium. Without enough vitamin D, the body can only absorb 10% to 15% of dietary calcium, but 30% to 40% absorption is the rule when vitamin reserves are normal. A lack of vitamin D in children causes rickets; in adults, it causes osteomalacia. Both bone diseases are now rare in the United States, but another is on the rise — osteoporosis, the “thin bone” disease that leads to fractures and spinal deformities.

Low levels of vitamin D lead to low bone calcium stores, increasing the risk of fractures. If vitamin D did nothing more than protect bones, it would still be essential. But researchers have begun to accumulate evidence that it may do much more. In fact, many of the body’s tissues contain vitamin D receptors, proteins that bind to vitamin D. In the intestines, the receptors capture vitamin D, enabling efficient calcium absorption. But similar receptors are also present in many other organs, from the prostate to the heart, blood vessels, muscles, and endocrine glands. And work in progress suggests that good things happen when vitamin D binds to these receptors. The main requirement is to have enough vitamin D, but many Americans don’t.

Vitamin D deficiencies

Vitamin D deficiencies were rare when most men rolled up their sleeves to work in sunny fields. But as work shifted from farms to offices, that changed. Because pigmentation can reduce vitamin D production in the skin by over 90%, nonwhite populations are at particular risk. Deficiencies are also common in patients with intestinal disorders that limit absorption of fat and those with kidney or liver diseases that reduce the conversion of vitamin D to its active form, calcitriol (1,25(OH)2D). In addition, certain medications reduce the availability or activity of vitamin D. And even in healthy people, advancing age is linked to an increased risk of vitamin D deficiency.

Although standards vary, most experts agree that levels of 25(OH)D below 20 ng/ml (nanograms per milliliter) reflect clear-cut vitamin D inadequacy, while levels between 20 and 30 ng/ml are borderline.

A number of factors can play a role. Limited exposure to sunlight heads the list. Except during the short summer months, people who live at latitudes above 37 degrees north or below 37 degrees south of the equator don’t get enough UVB energy from the sun to make all the vitamin D they need. The same is true for people who spend most of their time indoors and for those of us who avoid sunshine and use sunscreens to protect our skin from the harmful effects of ultraviolet radiation (see box below). It’s an example of an unforeseen consequence of wise behavior, but you can enjoy sun protection and strong bones, too, by taking vitamin supplements.

These many factors explain why vitamin D deficiencies are shockingly common in the United States. Although standards vary, most experts agree that levels of 25(OH)D below 20 ng/ml (nanograms per milliliter) reflect clear-cut vitamin D inadequacy, while levels between 20 and 30 ng/ml are borderline. Using similar criteria, American researchers have reported deficiencies in 42% of African American women aged 15 to 49, in 41% of non-hospitalized patients aged 49 to 83, and in up to 57% of hospitalized patients. And low levels of vitamin D are common even in apparently healthy young adults; in one study, more than a third of people between the ages of 18 and 29 were deficient.

Numbers can never tell the whole story, but in this case, “D-ficiencies” add up to a wide range of health concerns.

Osteoporosis and fractures

It’s a paradox: Skeletal health is the best-known contribution of vitamin D, but it has also become the most controversial. Although doctors agree that vitamin D deficiency increases the risk of osteoporosis and fractures, they disagree about the benefits and optimal dosage of supplements.

Without enough vitamin D, the intestines cannot efficiently absorb calcium. But because blood calcium is critical for neuromuscular and cardiac function, the body does not allow levels to fall. Instead, it pours out parathyroid hormone, which mobilizes calcium from bone. Blood calcium levels remain normal, so your heart and nerves keep working nicely. But your bones bear the brunt: As bone calcium density falls, bones become weak and fracture-prone.

Most studies show that a lack of vitamin D increases the risk of osteoporosis and the likelihood of hip and other non-spinal fractures. But there is considerable disagreement about how much supplements reduce the risk of fractures. Some studies include only women, others both men and women; some include only frail, elderly, or institutionalized subjects, others physically active people; some use vitamin D alone, others a combination of D and varying doses of calcium; and some administer 400 international units (IU) of vitamin D a day, others up to 800 IU a day.

Prostate cancer

Some men mistakenly dismiss osteoporosis as a women’s worry, but none fail to recognize the importance of prostate cancer.

Vitamin D has an important role in regulating cell growth. Laboratory experiments suggest that it helps prevent the unrestrained cell multiplication that characterizes cancer by reducing cell division, restricting tumor blood supply (angiogenesis), increasing the death of cancer cells (apoptosis), and limiting the spread of cancer cells (metastasis). Like many human tissues, the prostate has an abundant supply of vitamin D receptors. And, like some other tissues, it also contains enzymes that convert biologically inactive 25(OH)D into the active form of the vitamin, 1,25(OH)2D. These enzymes are much more active in normal prostate cells than in prostate cancer cells.

Do the results from these experiments translate into clinically important effects? Possibly.

In 1998, Harvard’s Health Professionals Follow-up Study of 47,781 men reported that a high consumption of calcium supplements was associated with an increased risk of advanced prostate cancer. The risk was greatest in men getting more than 2,000 mg of calcium a day from a combination of supplements and food. Since then, other studies have confirmed a link between very high levels of calcium intake and increased risk, but they have exonerated dietary calcium consumption. The Harvard scientists speculate that the problem is not calcium itself but a relative lack of active vitamin D.

Other malignancies

The risk of colon cancer, breast cancer, and other malignancies appears to rise in populations at latitudes far from the equator. Sun exposure and vitamin D levels may be part of the explanation. A recent clinical trial looking at a daily 1,000 IU vitamin D supplement did not show a decreased risk of cancer, but it was associated with a decreased risk of cancer death.

“D” right amount

The most widely used recommended dietary allowance (RDA) for vitamin D is 600 IU daily for adults up to age 69 and 800 IU daily for people older than 70.

Is more better? We don’t know yet, but you definitely can get too much of a good thing. Like the other fat-soluble vitamins, vitamin D is stored in the body’s adipose (fat) tissue. That means your body can mobilize its own reserves if your daily intake falters temporarily — but it also means that excessive doses of vitamin D can build up to toxic levels. At those extremes, vitamin D can raise blood calcium to levels that can cause grogginess, constipation, and even death. But it takes massive overdosing to produce toxicity.

How to get vitamin D

You can make your vitamin D the old-fashioned way, by exposing your skin to UVB radiation in sunlight. It doesn’t take much, but people living north of the 37-degree-latitude line — roughly the imaginary line between Philadelphia and San Francisco — can’t get enough UVB in winter to do the trick. And many others will find it all too easy to overdose on UVB, increasing their risk of malignant melanomas and other skin cancers, as well as wrinkles and premature skin aging. All in all, most doctors recommend avoiding sunlight (see box) and getting vitamin D by mouth.

Diet can help, but it’s very hard to approach the new goals with food alone. Fish and shellfish provide natural vitamin D (oily fish are best), but you’ll have to eat about 5 ounces of salmon, 7 ounces of halibut, 30 ounces of cod, or nearly two 8-ounce cans of tuna to get just 400 IU. An egg yolk will provide about 20 IU, but since it also contains nearly a day’s quota of cholesterol, you can’t very well use eggs to fill your tank with D. Other foods have even less D, which is why manufacturers fortify milk, some yogurt, some orange juice, and many cereals with vitamin D. In general, a serving will provide about 100 IU; that means drinking a quart of fortified milk to get 400 IU.

Most people require supplements to get the vitamin D they need. It’s the main benefit of a daily multivitamin; most provide 400 IU. Remember to read the labels carefully so you won’t get too little or too much. And although cod liver oil is rich in vitamin D, it has too much vitamin A for regular use.

New light on the sunshine vitamin

It used to be simple: just get a “healthy” tan and your body will make all the vitamin D it needs. Desk jobs and sunscreen have changed all that, just as research is underlining the importance of vitamin D and suggesting its possible role in preventing many health problems. That makes vitamin D a dilemma of modern life that has a modern solution: eating fish and drinking some low-fat fortified milk, along with judicious doses of vitamin D supplements.

10 Mistakes You Make When Taking Vitamins and Trace Elements – An Endocrinologist Says

Nutrition

How can I take vitamin D and omega-3s to get the benefit and not the harm? Why is it important to examine the level of iron (ferritin) and how to increase the absorption of a capricious trace element? Doctor of the highest category, endocrinologist of the Pirogov clinic and author of the popular Instagram blog about endocrinology Natalya Liberanskaya shared useful recommendations.

Error No. 1. Do not control the level of vitamin D

Vitamin D has a positive effect on insulin resistance and metabolism, the body’s ability to withstand SARS and oxidative stress, reduces the risk of developing cancer and abnormalities in the development of the fetus during pregnancy. Moreover, “sunshine” vitamin D helps not to mope and reduces pain during childbirth.

In regions with low levels of insolation (including St. Petersburg), vitamin D deficiency is extremely common. However, it is not worth taking it as a preventive measure, since vitamin D is still a steroid hormone. Only after a special laboratory blood test for D-hormone can its level in the body be determined, and then the deficiency can be corrected.

Mistake #2. Taking calcium without normalizing vitamin D and magnesium levels

Calcium is an important mineral that maintains good bones and teeth, is responsible for blood clotting and growth, and maintains muscle and nervous system tone. Sufficient calcium intake is necessary for the prevention and treatment of osteoporosis, as well as arterial hypertension.

But calcium is not absorbed if the body is deficient in vitamin D and magnesium. Taking calcium in this case is simply meaningless.

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Error No. 3. Do not know which vitamin D is taken

Holekalciferol – an inactive form of vitamin D, it is precisely it is needed for it correction of its deficiency so that all body systems work properly and you feel good. The drug cholecalciferol is safe – the likelihood of overdose is small. But there is another, active form of vitamin D – calcitriol. It can be taken only under the supervision of a physician and for medical reasons.

Mistake #4. Taking vitamin D does not always mean normalization of its level

Vitamin D is poorly absorbed in the following situations: absorption of fats.

Mistake No. 5. Ignore Omega-3

Why take Omega-3 polyunsaturated acid? It preserves visual acuity, beauty and protects the vascular endothelium from damage. 30% of the brain is made up of omega-3 fatty acids. The substance is not synthesized in the body on its own. Unfortunately, even adherents of the Mediterranean diet do not always get enough omega-3s. The fatty acid is found in oily fish, linseed, sea buckthorn and mustard oils.

Adults should take 2 g of omega-3s daily and more. The exact dosage can be selected after an analysis called the Omega-3 index.

The advantage of Omega-3 in capsules over the same red fish lies in the good purification of fatty acids from harmful impurities that we can get along with fish caught in a pond.

Mistake No. 6. Do not distinguish between Omega-3 and Omega-6

Omega-3 and Omega-6 are useful and important unsaturated fatty acids for the body. However, there is no need to take Omega-6 additionally – we get this component in sufficient quantities from food from vegetable oils, poultry meat, oatmeal, etc. An excess of Omega-6 can play into the hands of inflammatory processes in the body.

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Mistake #7: Ignore iron (ferritin) weakness, dry skin, hair loss. Women are at risk for iron loss due to menstruation, do not get the right amount of this trace element and vegetarians.

Mistake No. 8. Taking iron blindly

In terms of assimilation, iron is a particularly capricious trace element. It should be taken with extreme caution. It’s not even that the drug in drops stains tooth enamel. Excess iron is deposited in the internal organs (liver, pancreas, thyroid gland), leading to serious disorders: hemochromatosis, cirrhosis, hepatitis, melasma (dusty-bronze skin color).

Iron is poorly absorbed from dairy products and coffee. On the contrary, vitamin C, B12, folic acid contribute to the favorable absorption of iron. If iron is poorly absorbed, the doctor prescribes special complexes.

Error No. 9. Sports supplements – trust and not check

Some athletes take proteins to accelerate muscle growth and “drying”. One of the most popular today is casein, which is made from ordinary cow’s milk. Casein protein is cheap to produce, but it is not suitable for everyone. Why is casein bad? Once in the body, it turns into casomorphin, which is addictive, can provoke inflammation of the intestinal mucosa, autoimmune diseases, swelling and lethargy.

Protein casein should not be taken by those who have problems with the gastrointestinal tract, as well as individual intolerance to lactose and casein.

Error No. 10. Not only collagen and hyaluronic acid are useful for the skin

After 35-40 years, the skin ages. Many women have a lack of collagen peptides and hyaluronic acid: in this case, injectable cosmetology and capsules come to the rescue as an auxiliary method of combating signs of age-related changes. However, other components are also useful for the skin:

• Sex hormones;
• Vitamin C;
• Sulfur;
• Silicon;
• Iron;
• Zinc.

Source: Pirogov Multidisciplinary Clinic.

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Author:

Katerina Reznikova,
August 21, 2020

Vitamin D: how to take, norms for children and adults

1. What is vitamin D
2. Benefit
3. Vitamins D2 and D3: What’s the difference
4. Shortage
5. Oversupply
6. Sun and Vitamin D
7. How to get vitamin D from food
8. Preservation of vitamin D in foods
9. How to replace the sun
10. Physician’s comment

What is vitamin D and why is it needed?

The main function of vitamin D is to promote the absorption of calcium and phosphorus. This substance strengthens bones and helps brain function, which is especially important for children during their growth period. Vitamin deficiency leads to a breakdown and weakening of the immune system, a predisposition to colds, diseases of the teeth and bones [1].

How much vitamin D you need depends on many factors. These include age, race, seasonality, sun exposure, clothing, and more. According to the recommendations of the US Institute of Medicine, an average daily dose of 400-800 IU, or 10-20 micrograms, is sufficient for 97.5% of people [2]. However, some studies have shown that the daily dose should be higher if you rarely go outside. So, for healthy people there are recommendations in the range of 1120-1680 IU. At the same time, patients with deficiency are prescribed up to 5000 IU [3]. People who are overweight or obese may also need more vitamin D [4]. In any case, do not take any vitamins without a doctor’s prescription.

Tsaturyan Sofya Sergeevna, endocrinologist, pediatric endocrinologist of the network of clinics 1000 IU / day), from 4 months to 4 years – 1000 IU / day, 4-10 years – 1500 IU / day, 10-16 years – 2000 IU / day of vitamin during the year.

Vitamin D dosage during pregnancy is up to 4000 IU”

Proven benefits of vitamin D

Fights disease

Studies confirm that vitamin D reduces the risk of multiple sclerosis and cardiovascular disease [5] [6]. A sufficient amount of the substance in the body is associated with a lower likelihood of colds and flu [7].

Reduces symptoms of depression

Vitamin D affects mood [8]. Surveys confirm that patients diagnosed with depression felt better after a course prescribed by doctors. Another study involved people with fibromyalgia. Scientists have indicated that vitamin D deficiency is more common in those who experience increased anxiety and depression [9].

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Supports weight management

People who took daily calcium and vitamin D supplements were able to shed excess weight faster than patients who received placebo [10]. Doctors have proven that extra calcium and vitamin D suppress excessive appetite.

Improves stamina

Studies of 310 adults, 67% women, spanned four weeks to six months. Scientists have concluded that vitamin D can increase the physical strength of the upper and lower extremities [11].

Vitamins D2 and D3: the difference

There are two forms of vitamin D in the diet:

1. Vitamin D2 (ergocalciferol): found in some mushrooms.
2. Vitamin D3 (cholecalciferol): found in fatty fish, fish oil and egg yolks. It is mainly produced by ultraviolet radiation.

D3 is the more potent of the two types and increases blood levels of vitamin D almost twice as much as D2 [13]. Any excess of the substance is stored in the body for later use. Every cell has a receptor for D vitamins, as they are essential for many processes, including bone health and immune system function [14].

What causes vitamin D deficiency

Vitamin D acts as a hormone, produced from cholesterol in sunlight. Although it is found in some foods, it is quite difficult to make up for the deficiency through nutrition alone. The recommended daily dose for an adult is 400-800 IU, but sometimes doctors advise to consume more. In Russian recommendations 2000 IU. According to a 2011 study, 41.6% of US adults are vitamin D deficient. This number reaches 69.2% among Hispanics and 82.1% among African Americans [15]. Scientists identify several risk factors that affect the lack of a substance in the body:

• dark skin;
• overweight;
• lack of fish and dairy products in the diet;
• distance from the equator, living in regions where there is little sun.
• oversupply of SPF products;
• sedentary lifestyle, long stay indoors.

The most obvious factor in the lack of this vitamin is the lack of sun, prolonged exposure to indoors, especially without windows [16]. As people age, their skin’s response to UV light decreases, and a sedentary lifestyle exacerbates the problem. Closed clothing also prevents the production of the substance, even if you walk all day. Moreover, the darker the skin, the higher its protection from the sun, respectively, previtamin is supplied in smaller quantities. Keep in mind that it lingers in adipose tissue, so being overweight is also the cause of poor absorption of the vitamin.

Only a doctor can diagnose vitamin deficiency. Therefore, it is important to seek the advice of a specialist, and not to make independent appointments.

Too much vitamin D

Most people don’t get enough vitamin D, so supplements are common. However, this substance can accumulate and reach toxic levels in the body, especially as a result of uncontrolled use of pharmaceutical drugs. Vitamin D intoxication occurs when its blood level rises above 150 ng/mL (375 nmol/L). Because the vitamin accumulates in adipose tissue and slowly enters the bloodstream, the effects of toxicity may persist for several months after supplementation is stopped [17]. The main effects of an excess of vitamin D:

1. Blood parameters. Doctors rely on figures of 40–80 ng/mL (100–200 nmol/L). Their increase to values ​​of 100 ng. / ml (250 nmol / l) signal danger [18]. In one study, researchers looked at data from 20,000 people over a ten-year period. Only 37 people were found to have levels above 100 ng/mL (250 nmol/L) and only one person had true toxicity at 364 ng/mL (899 nmol/L) [19].
2. Increased calcium level. Vitamin D helps to better absorb calcium from food, this is one of its main roles in the body. However, hypercalcemia leads to dangerous symptoms such as indigestion, increased fatigue, abdominal pain, dizziness, and confusion. Normal blood calcium levels are 8.5–10.2 mg/dL (2.1–2.5 mmol/L). One study included 10 people who developed excessive calcium levels after taking high doses of vitamin D to correct a deficiency [20]. Four of them experienced nausea and vomiting, and three of them lost their appetite.
3. Stomach problems. Discomfort and diseases associated with digestion, including irritable bowel syndrome, may also indicate elevated calcium levels associated with vitamin D intoxication [21]. In one reported medical case, such symptoms developed in a 1.5-year-old child who was given 50,000 IU of vitamin D3 for three months [22]. They disappeared some time after the supplements were eliminated.
4. Loss of bone mass. Because vitamin D plays an important role in calcium absorption and bone metabolism, getting it is critical to maintaining bone strength. However, an excess of the substance leads to the opposite effect. Although many of the symptoms of vitamin D overuse are associated with high blood calcium levels, some researchers suggest that the consequence of increased dosage is low vitamin K2 levels [23]. One of the most important functions of the latter is to retain calcium in the bones and remove it from the blood. An excess of vitamin D reduces the activity of vitamin K2 [24].
5. Renal failure. Too much vitamin D leads to kidney damage. In one case study, a patient was hospitalized due to kidney failure, elevated blood calcium levels, and other symptoms after receiving vitamin D injections prescribed by a physician [25]. In another medical experiment involving 62 people who received injections of excessively high doses of vitamin D, kidney failure was found in every patient. Moreover, regardless of whether they had healthy kidneys or previously diagnosed diseases associated with them [26].

However, it is not possible to achieve dangerous levels of vitamin in the blood due to prolonged exposure to the sun or only through food.

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How the sun helps produce vitamin D

The body converts UV rays into chemicals that become vitamin D3. Cholesterol processes previtamin D – it passes through the blood through the liver and kidneys, after which it turns into calcitriol. To replenish the amount of vitamin needed by the body, you need to be in direct sunlight, while more than half of the skin should be open. Studies show that the brighter the sun, the less time it takes to get vitamin D. Also, experts have calculated that in England it is enough to be outside for 13 minutes three times a week at noon. Try to follow the rules of tanning and protect the skin from burns.

Most residents of the northern regions should not expect to get their vitamin D from the sun alone. Even when you are on vacation in hot countries, and most of the time you are in the city, it is unlikely to be enough. Therefore, it is important that the vitamin enters the body, including with food. If you are diagnosed with a vitamin deficiency, your doctor will likely recommend adding meals to your diet daily with ingredients that are high in vitamin D. For severe deficiency, high-dose tablets or drops are prescribed.

How to get vitamin D from food

The Recommended Daily Allowance (DV) is 800 IU (20 µg) of vitamin D per day from food [27]. Food of animal origin is suitable for replenishing stocks: cheese, fish oil, kefir, egg yolk, butter, fish and oysters. Cod liver oil is the record holder for the content of vitamin D: in a teaspoon it is about 448 IU. Some plant foods also contain it, such as parsley, mushrooms, nettles, soy milk, and orange juice. Sometimes manufacturers additionally fortify foods with vitamin D by adding it to yogurt, milk, or oatmeal. It should be borne in mind that the content of the substance decreases during heat treatment. Before transportation, the fish is frozen, and before use it is cooked under the influence of high temperatures, as a result, some of the useful properties disappear.

How to preserve vitamin D in foods

In order to retain the maximum amount of useful substances in dishes, it is better not to soak meat and fish in water before cooking. Try defrosting them slowly, leaving them at room temperature. It is most useful to cook dishes by steaming, frying on the grill or baking in foil. Do not reheat food prepared the day before – this significantly reduces its beneficial properties. In addition, some products are dangerous to re-heat exposure.

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Sun replacement

Doctors advise adults to get at least 600 IU (international units) of vitamin D. These figures are higher for pregnant and breastfeeding women. The only sure way to replenish vitamin reserves without ultraviolet radiation is to use pharmaceutical preparations. As a rule, they are prescribed to children in the cold season. The “sunshine vitamin” is difficult to obtain in the right amount only through food (for example, you have to eat 20 eggs daily). It is much easier to use a water-soluble preparation or fish oil capsules (especially cod liver oil). Vitamin D overdose is unlikely unless you are taking more than 10,000 IU per day for a long time. However, before buying pharmacy drugs, you need to consult a therapist and take a blood test.

Expert comment

Tsaturyan Sofya Sergeevna, endocrinologist, pediatric endocrinologist of the Semeynaya clinic network

Vitamin D is taken strictly after meals. The vitamin is fat-soluble, and so it is better absorbed. Clinical guidelines use both an oil form and an aqueous solution. In our country, only liquid forms of vitamin D are allowed.