Description

The biochemistry of vitamin D is reviewed. The pathological consequences of vitamin D deficiency, particularly osteomalacia are described in detail, and the complicating effect of vitamin D insufficiency on osteoporosis is also described. An extensive review of the evidence on supplementation with vitamin D and calcium is presented, including the Royal College of Physicians statement on the use of calcium and vitamin D suggesting that calcium supplements of greater than 1gram of elemental calcium per day decreases loss of bone in women with osteoporosis, pharmacological amounts of calcium decrease the risk of vertebral fracture, vitamin D supplementation decreases bone loss in women with osteoporosis, and when this is combined with calcium supplementation there is a significant decrease in the risk of hip and other fractures in frail elderly women. The evidence for calcium and vitamin D supplementation in older men suggests that it may be useful but the results are not conclusive.