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Optimal Vitamin D Status for the Prevention and Treatment of Osteoporosis

MF Holick. Drugs and Aging, Jan 1, 2007:24(12):1017-29. Department of Medicine, Section of Endocrinology, Nutrition, and Diabetes, Vitamin D, Skin and Bone Research Laboratory, Boston University Medical Center, Boston, Massachusetts, USA.

Vitamin D(3) (cholecalciferol) sufficiency is essential for maximising bone health. Vitamin D enhances intestinal absorption of calcium and phosphorus. The major source of vitamin D for both children and adults is exposure of the skin to sunlight. Season, latitude, skin pigmentation, sunscreen use, clothing and aging can dramatically influence the synthesis of vitamin D in the skin. Very few foods naturally contain vitamin D or are fortified with vitamin D. Serum 25-hydroxyvitamin D [25(OH)D; calcifediol] is the best measure of vitamin D status. Vitamin D deficiency [as defined by a serum 25(OH)D level of <50 nmol/L (<20 ng/mL)] is pandemic. This deficiency is very prevalent in osteoporotic patients. Vitamin D deficiency causes osteopenia, osteoporosis and osteomalacia, increasing the risk of fracture. Unlike osteoporosis, which is a painless disease, osteomalacia causes aching bone pain that is often misdiagnosed as fibromyalgia or chronic pain syndrome or is simply dismissed as depression. Vitamin D deficiency causes muscle weakness, increasing the risk of falls and fractures, and should be aggressively treated with pharmacological doses of vitamin D. Vitamin D sufficiency can be sustained by sensible sun exposure or ingesting at least 800-1000 IU of vitamin D(3) daily. Patients being treated for osteoporosis should be adequately supplemented with calcium and vitamin D to maximise the benefit of treatment.