Vitamin D₃ promotes longevity in Caenorhabditis elegans

Vitamin D deficiency is associated with a variety of age-related diseases and is becoming increasingly more prevalent in the population over time. Some diseases associated with deficiency are cardiovascular disease, cancer, and neurodegeneration. This association, as well as the fact that vitamin D has been demonstrated to play an important role in a variety of extraskeletal processes, has led some to claim that vitamin D is an essential longevity vitamin. However, the role of vitamin D in healthy aging has been difficult to determine. In order to study vitamin D in the context of aging, the model organism, Caenorhabditis elegans (C. elegans), was employed. To study vitamin D's impact on aging and age-related disease, lifespan and health span were measured across three different genetic strains of C. elegans. Strains investigated were wildtype (N2), worms with a mutant vitamin D receptor ortholog (nhr-8), and worms engineered to represent Alzheimer disease (gnals2). Bioinformatic analysis of available public data was also performed in order to identify the transcriptional response produced in N2 worms treated with vitamin D₃. Treatment with vitamin D₃ significantly extended the lifespan of N2 worms and rescued nhr-8 worms, which typically have decreased lifespans compared to N2. Treatment with vitamin D₃ minimally extended the lifespan of gnals2 worms. Similar results were obtained for measures of health span, quantified as motility through time. Differentially expressed genes upon treatment with vitamin D₃ were largely associated with biological processes such as the innate immune response and metabolism of xenobiotic compounds in the worms, which may explain the observed increase in lifespan and health span.