Vitamin D supplements might slow cellular aging by preventing the loss of telomeres, DNA sequences at the ends of chromosomes that shorten in old age, a new study suggests. The health effects of these findings aren’t yet clear.
Vitamin D had been touted as a panacea for a number of health conditions, from cardiovascular disease to bone loss. In 2020 a large randomized controlled trial of supplementation instead found benefits only in a few conditions, particularly autoimmune disease and advanced cases of cancer, says the new study’s co-author JoAnn Manson, a professor of medicine at Harvard Medical School and a principal investigator of that large trial, called the VITamin D and OmegA-3 TriaL (VITAL). The new study is an analysis of data from VITAL. Its finding could explain the protective effect of vitamin D supplements on these specific aging-related diseases, Manson says.