Vitamin D deficiency: a risk factor for osteomalacia in the aged.

Deficiency of vitamin D is rare in the general population of the North American continent because of the availability of sunlight, vitamin D-fortified milk, and over-the-counter preparations containing the vitamin. Yet there are among the aged those who are at risk of developing a deficiency of the vitamin because of lack of exposure to sunlight and failure to ingest milk or vitamin supplements containing vitamin D. Four cases of vitamin D-deficiency osteomalacia are described, demonstrating the various findings in the patient history and the physical, radiologic, and laboratory evaluation. In all cases physiologic doses of the vitamin corrected the abnormality quickly and fully. Vitamin D deficiency can be prevented prophylactically once the gerontologist is alert to the fact that some elderly people, who are easily identifiable by history alone, are likely to develop such deficiencies.