Vitamin D and Immunity: Walking on Sunshine, Does it Make Us Feel Good?

Background: Vitamin D has long been known to have an active role in innate and adaptive immunity in humans. Historically vitamin D has been found to play a major role in the regulation of the immune system in by Cantorna, M., Zhu, Y., Froicu, M., & Wittke, A. (2004) due to the location of vitamin D receptors on peripheral blood mononuclear cells.   Low vitamin D levels have been linked to many diseases such as cardiovascular disease, lung and respiratory disease, bone disease and certain cancers according to Scacchetti, A., Cariani, E., Manieri, G., Vecchi, C., & Trenti, T. (2014).  Ginde, A., Mansbach, J., &  Camargo, C. (2009), have found low vitamin D levels to be associated with the presence of serum IgE manifesting in increased allergy symptoms in individuals. Martineau, A., Wilkinson, R., Wilkinson, K., & Newton, S. (2007) established that a single dose of vitamin D can enhance immunity to mycobacteria, which may have benefits in the prevention of Tuberculosis. While vitamin D and the benefits to bone health have been known for years, it is the new evidence in the literature that supports the belief that suboptimal circulating serum vitamin D levels  has a significant abrogating effect on healthy autoimmune fuction, cardiovascular health and protection against certain cancers according to Hewison (2012). These preventative effects seem to rely on  the localized activation of vitamin D, Hewison ( 2012). Vitamin D levels and the immune protection it offers  is not solely reliable on supplementation,  the American Diabetes Association (2012)  found a profound effect on the body's Immune cells and their ability to function if there was insufficient circulating vitamin D. Part of the recommendations,  according to researchers, is that  sunshine is just as effective and important in treating those with Tuberculosis, due to it's ability to alter  body vitamin D levels in a positive manner.

Purpose:To identify evidenced-based data to support the hypothesis that vitamin D is essential to maintaining a healthy immune system, and maintaining circulating serum blood levels within a “normal” reference range which may be one way advance practice nurses can prevent the onset of multisystem disease. To prepare a comprehensive review of the literature on the subject of vitamin D and the relationship to immunity. This state -of-the -art  literature review would serve as a foundation upon which  researchers could  focus future research  in order to establish practice  guidelines on vitamin D supplementation in an effort to prevent disease.

Methods: Fifty-six articles were selected from a review of literature using key words   (vitamin D, immunity, cardiovascular disease, respiratory disease, cancer, allergies, bone disease and serum vitamin D levels in humans). CINAHL and PUBMED data bases were explored with a five year date restriction except when establishing significant historical scientific data to capture the range of disease that has been found to have associations with serum vitamin D levels.  Articles were selected based on establishing the best-evidence based guidelines, standards of care, and relevance to advanced practice nursing in providing disease prevention.

 Results: A review of the literature on vitamin D and immunity supplied evidence that a relationship exists between vitamin D and innate and adaptive immunity.  The literature also supported the hypothesis that low serum vitamin D levels may be related to the existence of multiple disease states in human beings. Supplementation of vitamin D was shown to enhance immunity to bacteria such as mycobacteria in Tuberculosis and potentially inhibiting the reactivation of latent Tuberculosis in individuals.

Conclusions: Clinically efforts should be aimed to supplement vitamin D levels to boost both innate and adaptive immunity to prevent and alleviate diseases linked to low circulating  vitamin D levels.

Implications: Further research needs to be done to specifically determine the link between the supplementation of vitamin D with the goal to keep serum vitamin D levels within a normal to high of the normal reference range likely augmenting innate and adaptive immune responses in humans to prevent or alleviate multiple disease states.