What Is Vitamin D And What Does It Do?

Vitamin D is a nutrient found in some foods that are necessary for the health and maintenance of healthy bones. Vitamin D helps the body absorb calcium (one of the basic building blocks of bones). People who receive too little Vitamin D can develop soft, thin and brittle bones, a condition known as rickets in children and osteomalacia in adults.

Vitamin D is also important to the body in many other ways. Muscles need it to move, for example nerves need it to convey messages between the brain and every part of the body, and the immune system needs vitamin D to fight off invading bacteria and viruses. Along with calcium, vitamin D also helps protect the elderly from osteoporosis. Vitamin D is found in cells throughout the body.


How Much Vitamin D Do I Need?

The amount of vitamin D you need each day depends on your age. Average daily recommended amounts for different ages are listed below in International Units (IUs):

Age Recommended Admission:
Birth up to 12 months 400 IU
Children 1-13 y. 600 IU
Teens 14-18
600 IU
Adults 19-70 years 600 IU
Adults over 71 800 IU
Pregnant and lactating women 800 IU

What Foods Provide Vitamin D?

Very few foods naturally have Vitamin D.

> Oily fish such as salmon, tuna and mackerel are among the best sources.
> Veal liver, cheese, mushrooms and egg yolks provide small amounts.
> Vitamin D is found in milk as well as in soy, almond and oat milk.


Can I Get Vitamin D From The Sun?

The body makes vitamin D when the skin is directly exposed to the sun and most people meet at least some of their vitamin D needs that way. Skin exposed to the sun indoors through a window will not produce vitamin D. Cloudy days, shade and dark skin also reduce the amount of vitamin D that the skin does.

Despite the importance of the sun for the synthesis of vitamin D, it is wise to limit the skin's exposure to sunlight in order to reduce the risk of skin cancer. When outside in the sun for more than a few minutes, wear protective clothing and apply sunscreen with SPF (sun protection factor) of 8 or more. Tanning also causes the skin to produce vitamin D, but poses a similar risk for skin cancer.

People who avoid the sun or cover their body with sunscreen or clothing should include good sources of vitamin D in their diets or take the vitamin as a dietary supplement.

What types of vitamin D supplements are available?
Vitamin D is found in supplements (and fortified foods) in two different forms:

D2 (ergocalciferol) and D3 (cholecalciferol). Both increase Vitamin D in the blood.


Am I getting enough Vitamin D?

Since Vitamin D can come from the sun, food and supplements, the best measure to track how much Vitamin D you have is through a laboratory blood test.

Based on the results of your blood collection, it can be determined whether you are deficient in Vitamin D. (Consult your doctor for a medical examination).

At what age groups is vitamin D deficiency observed?
> In infants. Breastfed babies should receive a supplement of 400 IU of vitamin D every day.

> Older people because their skin does not produce enough vitamin D when exposed to sunlight as effectively as when they were young and their kidneys are less able to convert vitamin D to its active form.

> Dark-skinned people because their skin has less ability to produce Vitamin D from the sun.

> People with disorders such as Crohn's disease or celiac disease who do not handle fat properly because Vitamin D needs fat to be absorbed.

> Obese people because their body fat can prevent the vitamin from getting into the bloodstream.

What happens if I don't take enough Vitamin D?

People may be deficient in Vitamin D because they do not consume or absorb enough in their food, their exposure to sunlight is limited, or their kidneys cannot convert Vitamin D into its active form in the body. In children, vitamin D deficiency causes rickets, a condition in which the bones become soft and bend. In adults, vitamin D deficiency leads to osteomalacia, causing bone pain and muscle weakness.

Can Vitamin D Be Harmful?

Yes, when the blood levels get too high. Signs of toxicity include nausea, vomiting, poor appetite, constipation, weakness and weight loss. And by raising blood calcium levels, too much vitamin D can cause confusion, disorientation and heart rhythm problems. Excess vitamin D can also damage the kidneys.

The upper limit for Vitamin D is:


1000 to 1500 IU / day for infants
2 500 to 3000 IU / day for children 1-8 years
4000 IU / day for children 9 years and older, adults, pregnant and lactating teens and women.

Vitamin D toxicity is almost always derived from overuse of supplements. Excessive sun exposure does not cause vitamin D poisoning as the body limits the amount of vitamin it produces.

Are there any interactions with Vitamin D that I need to know about?

Like most nutritional supplements, Vitamin D can interact with or interfere with other medicines or supplements you may take. Tell your doctor or any nutritional supplements and medicines you are taking. They can tell you whether these nutritional supplements can interact with or interfere with your prescribed or over-the-counter medications, or whether the medications can prevent your body from absorbing, using, or breaking down nutrients.

Warning: This article, borrowed from the Food Additives Service (ODS), provides information that should not be replaced by medical advice. We encourage you to speak with a healthcare professional before using supplements and medications.

The article is translated and translated from English into Bulgarian.
You can see the full article of the National Health Institute here:
https://ods.od.nih.gov/factsheets/VitaminD-Consumer/?fbclid=IwAR0S92Dl