Vitamin D--the steroid hormone prescription for every patient

Physicians in the United States rarely screen for hypovitaminosis D and rarely prescribe vitamin D, even when medically indicated. This is of particular concern in Minnesota. The sun's intensity at Minnesota's latitudes limits vitamin D production, at best, to March through October. A variety of lifestyle situations, including long work hours, may preclude adequate sun exposure. Additionally, people of Northern European background may avoid sun exposure to reduce risk of skin cancer and premature aging. And people of Asian and African heritage may not have sufficient vitamin D production due to increased skin pigmentation. This brief article summarizes key points regarding the importance of vitamin D, including its action as a steroid hormone and its role in cancer, hypertension, and autoimmune disease as well as in perinatal and prenatal health. The potential benefit of hypovitaminosis D screening and vitamin D supplementation is discussed, as are the populations most likely to need screening and supplementation.