Vitamin D status is heritable and under environment-dependent selection in the wild

Vitamin D has a well-established role in skeletal health and is increasingly linked to chronic disease and mortality in humans and companion animals. Despite the clear significance of vitamin D for health and obvious implications for fitness under natural conditions, no longitudinal study has tested whether the circulating concentration of vitamin D is under natural selection in the wild. Here, we show that concentrations of dietary-derived vitamin D-2 and endogenously produced vitamin D-3 metabolites are heritable and largely polygenic in a wild population of Soay sheep (Ovis aries). Vitamin D-2 status was positively associated with female adult survival, and vitamin D-3 status predicted female fecundity in particular, good environment years when sheep density and competition for resources was low. Our study provides evidence that vitamin D status has the potential to respond to selection, and also provides new insights into how vitamin D metabolism is associated with fitness in the wild.

Automated summary

This study reveals that vitamin D levels in wild Soay sheep are genetically influenced and positively associated with female survival and fecundity. It provides evidence for the potential response of vitamin D levels to natural selection and offers new insights into the association between vitamin D metabolism and fitness in wild environments.