>> Jul 26, 2012
Vitamin D is different from most other vitamins because our bodies can make most of the vitamin D we need. Some foods are fortified with vitamin D (such as milk), but vitamin D mostly comes from the sun. The skin makes vitamin D from cholesterol when it is directly exposed to 10-20 minutes of sunlight, especially in the summer months. So if your body can make its own vitamin D, why are so many people deficient?
Certain population groups are more prone to vitamin D deficiency. People with darker skin do not absorb the vitamin as well as those with lighter skin. Also, people who live in colder climates, who have illnesses that prevent proper absorption of nutrients, and breastfed children who do not receive supplemental vitamin D, are all at risk for developing a deficiency. The elderly are at high risk due to time spent indoors and the fact that the skin no longer absorbs vitamin D as efficiently as we age.
Why is vitamin D important?
The major role of vitamin D is to help with the absorption of calcium and is vital to maintain bone health. Vitamin D also plays a role in muscle movement and helps the immune system fight bacteria and viruses. There has been research linking too low of levels of vitamin D to certain cancers like thyroid, prostate, and breast cancer. Research has shown that vitamin D may play a role in the prevention of diabetes and hypertension, although the exact mechanism has not been discovered. Vitamin D can also be related to difficulty losing weight. People who are obese tend to have lower levels of vitamin D, as vitamin D is fat soluble and gets trapped in the body’s fat cells.
How do I know if I am deficient and what should I do?
Vitamin D deficiency can be determined via a simple blood test ordered by your doctor. If you are deficient, a doctor may prescribe up to 10,000 IU of the vitamin for a short time to help improve your levels. Most over-the-counter multivitamins contain about 600-800 IU of vitamin D which is enough to maintain normal blood levels. Be careful to check the total amount of vitamin D you are getting if you are taking a calcium supplement (with vitamin D) in addition to your regular multivitamin. The total for the day should not exceed 1000 IU from supplements. In most commercial vitamins, vitamin D is found in either the D2 (ergocalciferol) form or D3 (cholecalciferol). Many experts believe that D2 is not well absorbed or utilized because it comes from plants and not an animal source. Vitamin D3 more closely matches the type vitamin D found in the body; therefore it is the preferred form for supplementation. Do not worry about getting too much vitamin D from the sun, so get out there and enjoy the sunshine!