The study, published in Free Radical Biology and Medicine, manipulated serum vitamin D status in rats using dietary supplementation with low, moderate/control, or high levels of the vitamin from middle to old age in order to assess changes in vitamin D-dependent proteome expression in the brains of the rats.
Led by Professor Allan Butterfield from the University of Kentucky, the research team found that middle-aged rats fed a diet low in vitamin D (VitD) for several months developed free radical damage to the brain and a significant decrease in cognitive performance on tests of learning and memory - with redox proteomics showing that many different brain proteins were damaged.
"Given that vitamin D deficiency is especially widespread among the elderly, we investigated how during aging from middle-age to old-age how low vitamin D affected the oxidative status of the brain," explained Butterfield.
"This study is the first to demonstrate that a chronic low-VitD diet and consequential low levels of VitD in the bloodstream result in significant increases in tyrosine nitration in brain proteins, alterations in glucose metabolism, and mitochondrial changes in brain of elderly rats," said the team.