Vitamin D deficiency in welfare institutions for the aged.

Serum concentrations of 25-OH-D in a group of 47 elderly people (70--94 years old) living in homes for the aged were lower than those in a matched control group living in their homes. No differences between the groups were noted in serum ionized calcium, alkaline phosphatase, inorganic phosphate, magnesium or parathyroid hormone. The low serum concentration of 25-OH-D may be due to less outdoor activities and/or a smaller dietary vitamin D intake in the institutionalized group. The importance of preserving an adequate vitamin D status in geriatric patients is emphasized.