Vitamin D and muscle function in older people

Vitamin D deficiency is a worldwide problem particularly among older people, who are more susceptible due to diminished vitamin D synthesis in the skin and low dietary intake of vitamin D. Vitamin D has been associated with various (patho)physiological functions including muscle function. It is important to determine the effect of vitamin D on muscle function in older people because of the possible consequences for mobility. In 70 frail vitamin D insufficient older women the most important determinants of mobility were knee extension strength, physical activity and use of a walking aid. Fifty-three percent of the women had experienced a fall in the previous 6 months. Low knee extension strength, worse performance on the mobility tests, use of benzodiazepines and use of a walking aid were associated with fall occurrence. In 802 independently living volunteers between 40 and 80 yrs of age, 36% of the men and 51% of the women had a low vitamin D status (serum hydroxyvitamin D