Many Americans have been found to have low levels of vitamin D. The reasons for this include low availability of vitamin D in food sources, increased time working indoors, and possibly increased use of sunscreens (since sunlight helps the body produce vitamin D).
Certain people may benefit from vitamin D supplementation. However, there is conflicting evidence about the amount of vitamin D that is safe and effective, or even necessary, to use as a supplement.
Why do people take vitamin D?
Vitamin D is important for people with osteoporosis. Studies show that calcium and vitamin D together can increase bone density in postmenopausal women. Vitamin D also helps with other disorders associated with weak bones, like rickets.
People who have low levels of vitamin D may need supplements. Vitamin D deficiencies are more common in those who:
- Are over 50
- Get very little sun exposure
- Have kidney disease or diseases that affect the absorption of minerals
- Have darker skin
- Are lactose intolerant
- Are vegan
- Are infants who are fed only breast milk
Vitamin D deficiency is commonly seen in people living in the Northern parts of the U.S.
Studies have found prescription-strength vitamin D lotions helpful in treating psoriasis. Vitamin D has also been studied for other conditions ranging from cancer prevention to high blood pressure, but the evidence is unclear.