Vitamin D Source Supplement

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 D2. As a result, many supplements are being changed to include vitamin D3 instead of D2, 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.


DeNoon, D. (2008). Supplement your knowledge of vitamin D. Retrieved December 27, 2009 from the WebMD website:

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