Grant: Project Grant

Vitamin D was discovered for its role in bone health but is now recognized to have multiple physiological actions. One of its "non-classical" actions that has been intensively studied over the last few years is its role in the immune system. Notably, there are numerous links between vitamin D deficiency in early childhood and risk of development of autoimmune conditions. One of the key organs implicated in the recognition of "self" by the immune system and limiting autoimmunity is the thymus. Disrupted thymic function can lead to multiple autoimmune conditions. However, very little is known about the role of vitamin D in the thymus. We have found that vitamin D is active in many cell types in the thymus and have preliminary evidence that it regulates the function of key proteins implicated in immune recognition of self in the thymus. Our goals are to define in detail how vitamin D contributes in the thymus to the mechanisms that limit autoimmunity. These studies may have a major public health impact as vitamin D deficiency is widespread and they will provide evidence for the importance of routine vitamin D supplementation for infants and children.