Vitamin D plays an important role in muscle function and strength. Low vitamin D levels are associated with sarcopenia, or the loss of muscle mass and strength that occurs with aging. A study of over 800 men found that lower vitamin D levels were a significant determinant of lower relative appendicular skeletal muscle mass, even after adjusting for other factors. Another study of nearly 1,000 older adults found that lower vitamin D levels were associated with poorer performance on physical tests of mobility and strength. Maintaining adequate vitamin D levels may help reduce the risk of sarcopenia and falls in older adults.