High levels of vitamin D may slow aging and increase life span by preventing age-related decline in telomere length, according to a new study.
Telomeres are repetitive DNA sequences at the ends of chromosomes that shorten with aging, cell division, and inflammation. When telomeres become too short, the cell can no longer divide, and it becomes senescent or dies. For this reason, scientists seeking to extend lifespan have long been interested in methods to prevent telomere shortening.
Scientists at King's College, London studied more than 2,000 women, examining their serum levels of vitamin D and assessing leukocyte telomere length. Women with the highest levels of vitamin D had the longest telomeres, even after adjusting for age differences. Women with the lowest levels of vitamin D had the highest levels of C-reactive protein, a marker for chronic inflammation. Compared with women who had the lowest vitamin D levels, those with the highest levels had telomeres whose length correlated to roughly five additional years of life.
Increasing vitamin D levels through appropriate supplementation may therefore have important benefits for slowing aging and prolonging life.
Vitamin D refers to two biologically inactive precursors - D3, also known as cholecalciferol, and D2, also known as ergocalciferol. Vitamin D-3 is produced in the skin on exposure to UVB radiation (290 to 320 nm), and is 10 times more bioactive. Vitamin D-2 is derived from plants and only enters the body via the diet.
"Our findings suggest that higher vitamin D concentrations, which are easily modifiable through nutritional supplementation, are associated with longer [leukocyte telomere length], which underscores the potentially beneficial effects of vitamin D on aging and age-related diseases," the researchers concluded.
Richards JB, Valdes AM, Gardner JP, et. al. Higher serum vitamin D concentrations are associated with longer leukocyte telomere length in women. Am J Clin Nutr. 2007 Nov;86(5):1420-5.
Adapted with permission from an article in Life Extension, Feb 2008