Who should receive vitamin D supplementation?
Dr. Truong: Vitamin D comes from the diet and the skin. Skin production of the active form of vitamin D is dependent on exposure to sunlight. Active people living in sunny regions (Southern California, Hawaii, countries around the equator, etc.) can produce most of the vitamin D they need from their skin. Therefore, in Southern California where I have my practice, vitamin D supplementation is mainly used for housebound individuals or nursing home residents. In less temperate regions such as Minnesota, Michigan, and New York, skin production of vitamin D is markedly diminished in the winter months, especially among the elderly. In that population, dietary vitamin D becomes important. Unfortunately, vitamin D deficiency is quite common in the United States, especially among the elderly living in cold climates. In a study of hospitalized patients in a general medical ward, vitamin D deficiency was detected in 57% of the patients. An estimated 50% of elderly women consume far less vitamin
