Diabetes Plus Low Vitamin D Tied to More Muscle Loss in Old Age

Older people with diabetes who also had low vitamin D in their blood more often had age-related muscle loss in an English group. Muscle loss here meant a weak grip together with low estimated muscle mass. Across all participants, though, there was no clear link once other factors were taken into account.

Researchers looked at data from 7,520 people aged 50 or older in the US and England, each examined once. Low vitamin D meant 50 nanomoles per liter or less. In England, people with diabetes and low levels had muscle loss more often than people without diabetes and higher levels. The US group pointed the same way, but the result was not clear. The team also gave vitamin D3 to rats made artificially old and diabetic. Those rats gripped harder, and their muscles held about 72 percent less fat than rats lacking vitamin D.

The authors call the human findings suggestive, not confirmatory. Because everyone was measured only once, it is unclear which came first: low vitamin D or weak muscles. Whether vitamin D protects people with diabetes from muscle loss was not tested; supplements were given only to rats.