Low vitamin D in midlife linked to higher tau protein levels later, study finds

A study published in an open-access journal found that people with low vitamin D levels in midlife showed higher accumulation of tau protein, a key marker of Alzheimer's disease, in the years that followed. Researchers analyzed blood samples from 793 participants with an average age of 39 and conducted PET scans 16 years later. The results showed that participants with higher vitamin D levels had less tau protein buildup in their brains. The association was most pronounced in the temporal lobe and other memory-related regions typically affected in the early stages of Alzheimer's. The researchers reported no significant link between vitamin D levels and the buildup of beta-amyloid, another protein associated with the disease. The team stressed that the finding reflects a statistical association and does not prove that vitamin D supplementation prevents dementia. They said midlife vitamin D deficiency could still represent a modifiable risk factor for early neurodegenerative changes. A separate study published in Frontiers in Nutrition during the same period found that vitamin D deficiency may also be linked to an increased risk of head and neck cancer. Experts noted additional associations between vitamin D levels and conditions including cellular aging, depression and sudden hearing loss.