Vitamin D and Calcium Supplements

Many people have osteoporosis. While it's easy for most people to get vitamin D from the sun, some individuals can't get adequate amounts of vitamin D in this way. These people may need to take a vitamin D supplement.

In the United States, 37 percent of people have reported taking supplemental vitamin D. People who may need extra vitamin D include breast-fed infants, the elderly and individuals with certain health conditions.

What Is Vitamin D?

Vitamin D is a fat-soluble vitamin that helps your body absorb and process calcium and phosphorus. It also plays a role in cell growth, bone health and immune system function. Your body can make vitamin D when it is exposed to direct sunlight.

How Vitamin D Supplements Work

Vitamin D supplements are available in two forms: ergocalciferol (D₂) and cholecalciferol (D₃). In the past, scientists believed that ergocalciferol and cholecalciferol worked in the same way in your body. However, there is now evidence that vitamin D₃ may be more effective at raising blood levels of vitamin D than vitamin D_2. As a result, many supplements are being changed to include vitamin D₃ instead of D_2, and cholecalciferol is now the recommended form of vitamin D.

Do I Need A Vitamin D Supplement?

People may need to take a vitamin supplement if they are unable to get adequate vitamin D from sunlight or dietary sources.

Individuals who may need supplemental vitamin D include:

• Breastfed infants (the American Academy of Pediatrics recommends vitamin D supplements for all breast-fed babies, but you'll want to talk to your doctor before administering any medication to an infant).
• Individuals who are obese.
• Older adults, whose kidneys may not be able to process vitamin D efficiently.
• People who do not get a lot of sun exposure, or those who use sunscreen consistently.
• People with dark skin.
• People with fat malabsorption, such as Crohn's disease or celiac disease.
• Pregnant women.
• Those who have had gastric bypass surgery.

People with osteoporosis may also need to take supplemental vitamin D.

Researchers are currently studying whether vitamin D supplements may reduce the risk of a range of other health problems, from cancer to heart disease. While some people think that supplemental vitamin D may help reduce the risk of a number of serious conditions, the evidence for this is as of yet inconclusive.

Vitamin D Toxicity

Vitamin D toxicity is a possible side effect of excessive use of vitamin D supplements. In fact, almost all cases of vitamin overdose are tied to supplements. Currently, the Institute of Medicine recommends that adults limit vitamin D intake to about 2,000 IU per day. However, higher doses of vitamin D may be used to treat certain conditions (such as rickets). These high doses of vitamin D are safe when recommended by a doctor. In general, vitamin D toxicity does not become a problem unless intake is very high over an extended period of time.

Resources

DeNoon, D. (2008). Supplement your knowledge of vitamin D. Retrieved December 27, 2009 from the WebMD website: http://www.webmd.com/osteoporosis/news/20080519/supplement-your-knowledge-of-vitamin-d.

Kotz, D. (2009). How much vitamin D should you be taking? Retrieved December 27, 2009 from the US News