Vitamin D treatment and bone mineral density in the aged.

The purpose of this study was to investigate whether long-term vitamin D treatment increased bone mineral density in the aged. The bone mineral density in the distal forearm and femoral neck did not differ between nine residents (mean age 81.0 years) of an old peoples' home who had received an annual injection of 150,000 IU ergocalciferol during the foregoing 2-7 years (mean 5.1 years) and nine age-, weight- and height-matched control subjects who had subnormal 25 hydroxyvitamin D level. The alkaline phosphatase and parathyroid hormone levels were clearly higher when the 25 hydroxyvitamin D level was below 10 nmol/1. The authors suggest that the ability of vitamin D treatment to diminish fracture incidence may derive from improved bone quality, not measurable by the standard dual energy X-ray absorptiometry, and/or improved nervous and muscular control of movements to counter the tendency to fall.