For the study, published online in the journal JAMA Internal Medicine, Finnish researchers tracked 409 women over 70 who took daily vitamin D supplements and exercised, The New York Times reports. They were compared to three other groups of women who were given a placebo without exercising; took vitamin D without exercising, and engaged in physical activity with taking supplements.
After two years, those who took vitamin D alone were 16 percent less likely to be injured in a fall and those receiving a placebo who exercised were 54 percent less likely to be injured. But the seniors who exercised and took vitamin D supplements were 62 percent less likely to be hurt.
The authors noted physical activity and vitamin D increase bone density, which can help prevent injury.
"It's important to develop muscle power, because, without muscle power, you can't have good balance," said lead researcher Kirsti Uusi-Rasi, a senior researcher at the UKK Institute for Health Promotion Research. "If you have low levels [of vitamin D], supplements are important, but if you have sufficient levels, more is not better.