Vitamin D plays several key roles in your body. Most importantly, vitamin D helps your body absorb the minerals calcium and phosphorus from the food you eat, which is important for bone health.
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.
Vitamin D deficiency may cause hormone problems, muscle weakness and pain, and other symptoms.
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.