Nutritional hypovitaminosis-D and the genesis of osteomalacia in the elderly.

A review is presented of the genesis of osteomalacia due to dietary lack of vitamin D in the elderly in the United Kingdom. Subjects at high risk are identified and the diagnostic difficulties discussed. The importance of dietary vitamin D and exposure to sunlight in relation to vitamin status is stressed. The role of vitamin D in calcium metabolism is now much more clearly defined; the final active form of the vitamin is 1,25-dihydroxy-vitamin D, which acts like a hormone after the vitamin molecule has undergone two chemical modifications in the liver and kidney. A correlation between lack of vitamin D and femoral neck fractures has been established. Six illustrative cases of osteomalacia in the elderly due to dietary lack of vitamin D are reported.