Vitamin D- Your New Supervitamin

Here's a little ray of sunshine: Did you know that your body makes Vitamin D? Almost like plants and photosynthesis, your body makes Vitamin D when exposed to ultraviolet (UVB) rays from sunshine.  In fact, Vitamin D is known as the "sunshine vitamin" for this reason.  Unfortunately, an unintended negative consequence of our efforts to prevent skin cancer by avoidance of sun exposure and using sunscreen is Vitamin D deficiency in many people. 

What Is Vitamin D?

This nutrient has two main forms: ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3). Vitamin D2 is made by plants. Vitamin D3 is made by humans in the skin when it is exposed to ultraviolet-B (UVB) rays from sunlight. Foods may be fortified with vitamin D2 or D3.

What Is the Role of Vitamin D in the Body?

The major biologic function of vitamin D is to maintain normal blood levels of the minerals calcium and phosphorus. Vitamin D aids in the absorption of calcium, helping to form and maintain strong bones and preventing osteoporosis.

Recent research suggests that Vitamin D also roles in preventing many illnesses, including

-cancer (breast, rectal, ovarian, prostate, stomach, bladder, esophageal, kidney, lung, pancreatic, uterine, Hodgkin's lymphoma and multiple myeloma)

-heart disease

-dementia

-multiple sclerosis

-diabetes

-hypertension

-falls

-immunity

What Are Symptoms of Vitamin D Deficiency?

Many people have no symptoms.  When symptoms are present, they may include

-achiness

-muscle weakness

-fatigue

What Are Risk Factors for Vitamin D Deficiency?

-lack of Vitamin D in the diet

-poor absorption from the digestive tract due to certain medical conditions (inflammatory bowel disease, celiac disease)

-dark skin (prevents body from using sun exposure to make Vitamin D)

-lack of sun exposure (but it only takes 10 minutes of day of unprotected sun exposure for your body to get enough sun exposure to make vitamin D)

-kidneys unable to convert Vitamin D to active form- occurs with aging

-obesity

-elderly

-infants who are exclusively breastfed

What Foods Contain Vitamin D?

-fish and fish oil (cod liver oil)

-fortified dairy products

-egg yolks

-liver

How Do We Know if We Are Deficient?

-a simple blood test for 25-hydroxy Vitamin D can measure the level of Vitamin D in your blood.  A normal value is >=30.  Most doctors recommend treating if your level is<20.

How Much Vitamin D Do I Need?

-the average adult needs 800 to 1000 IU of Vitamin D daily (Vitamin D3, cholecalciferol, is thought to be 25% better at raising levels) than Vitamin D2, ergocalciferol

-if deficiency is diagnosed (a level of <20), some people recommend treating initially with very high doses of vitamin D: 50,000 IU of either Vitamin D3 or D2 once a week for 6-8 weeks, then 1000IU of Vitamin D daily afterward

-if insufficiency is diagnosed(serum level of 20-30), 1000IU of vitamin D3 daily is recommended

-both Vitamin D3 and Vitamin D2 are available over the counter in capsule forms

-Vitamin D2 is also available in a liquid form

-if your doctor diagnoses you with malabsorption due to gastrointestinal issues, you may needed higher doses, in the range of 10,000-50,000 IU daily.  If these doses are insufficient, hydroxylated forms may be needed

Can I Get TOO Much Vitamin D?

Yes, and the signs would include elevated levels of calcium in your blood and urine. You may develop kidney stones, vomiting, and muscle weakness.

Because there can be too much of a good thing, it is important to recheck your Vitamin D level 3 months after starting supplementation.

Unless your doctor has diagnosed you with actual Vitamin D deficiency (a level of less than 20), you should limit your intake to no more than 1000IU daily.