Vitamin D

Vitamin D Information Image

What if there was a vitamin that could help keep your bones healthy and strong? And what if that vitamin might also help reduce your risk of certain cancers and other serious diseases, from asthma to diabetes?

This vitamin exists — vitamin D. And the good news isn’t just that vitamin D has numerous proven and suspected health benefits. It’s that you may not even need to alter your diet to get enough of this key nutrient. That’s because vitamin D is the only vitamin that is manufactured by our bodies. Many people can get all the vitamin D they need just by spending a few minutes in the sun every day. That’s a prescription almost everybody can live with.

What Is Vitamin D?

Vitamin D is a fat-soluble vitamin that you body uses to process and absorb calcium and phosphorus. This element, in turn, helps keep your bones strong and healthy. In fact, vitamin D is added to most milk sold in the United States precisely for this reason. Before the introduction of vitamin D-fortified milk in the 1930s, rickets (or soft bones) was a serious childhood health problem. Since then, rickets has become a relatively rare childhood illness, at least in U.S. children.

Doctors have long known about the important role that vitamin D plays in maintaining healthy bones. But there is now a growing body of evidence that vitamin D may help reduce your risk of certain cancers, heart disease, depression, arthritis and numerous other conditions. For instance, a study published in the May 2009 issue of the American Journal of Respiratory and Critical Care Medicine found that children with low levels of vitamin D were more likely to experience severe asthma. And a 2007 study found a link between vitamin D supplementation and a reduced risk of common cancers in women.

Vitamin D Deficiency

It’s important to get an adequate amount of vitamin D. Foods and supplements are two sources of vitamin D, but the easiest way to get vitamin D is usually through exposure to the sun. However, many people suffer low vitamin D levels. In children and adults, serious health problems (such as osteoporosis and rickets) can be caused by low levels of vitamin D. Symptoms of a vitamin D deficiency include bone pain, muscle aches and weakness.

Most people get the vitamin D they need from the sun. Vitamin D can also be found in certain foods, such as:

  • Beef liver
  • Egg yolks
  • Salmon
  • Tuna.

Some people (such as those with dark skin, or breast-fed infants) may not get enough vitamin D from the sun or their diet. These individuals may need to take vitamin D supplements. However, you should always speak to your doctor about starting a new supplement to ensure it won’t react with current medications.


Gever, J. (2009). Vitamin D deficiency linked to asthma severity. Retrieved December 10, 2009, from the MedPage Today website:

Lappe, J. et al. (2007). Vitamin D and calcium supplementation reduces cancer risk. Retrieved December 10, 2009, from the American Journal of Clinical Nutrition website:

Mann, D. (2009). Heart patients lacking vitamin D more likely to be depressed. Retrieved December 10, 2009, from the CNN website:

MedlinePlus (2008). Rickets. Retrieved December 10, 2009, from the MedlinePlus website:

Merck Home Manual. (n.d.). Vitamin D. Retrieved December 10, 2009, from the Merck website:

National Institutes of Health, Office of Dietary Supplements. (2009). Dietary Supplement Fact Sheet: Vitamin D. Retrieved December 10, 2009, from the National Institutes of Health website: