Vitamin D, often referred to as the "sunshine vitamin," is a fat-soluble secosteroid that plays a critical role in numerous physiological processes. Unlike most vitamins, the body is capable of synthesizing vitamin D endogenously through sun exposure. Nevertheless, deficiency remains one of the most prevalent nutritional disorders in the modern world.

Adipose tissue sequesters fat-soluble vitamins, including vitamin D.

Holick, M.F. (2007). Vitamin D deficiency. New England Journal of Medicine, 357(3), 266–281.

https://doi.org/10.1056/NEJMra070553

Holick, M.F., Binkley, N.C., Bischoff-Ferrari, H.A., et al. (2011). Evaluation, treatment, and prevention of vitamin D deficiency: An Endocrine Society clinical practice guideline. Journal of Clinical Endocrinology & Metabolism, 96(7), 1911–1930.

Bishop, N.J., Fewtrell, M.S., & Maclennan, A.H. (2019). Rickets prevention and management. Archives of Disease in Childhood, 104(7), 620–629.

Willett, W.C., & Ludwig, D.S. (2020). Milk and health. New England Journal of Medicine, 382, 644–654.

Garland, C.F., Gorham, E.D., Mohr, S.B., & Garland, F.C. (2009). Vitamin D for cancer prevention: Global perspective. Annals of Epidemiology, 19(7), 468–483.

Bouillon, R., Marcocci, C., Carmeliet, G., et al. (2019). Skeletal and Extraskeletal Actions of Vitamin D: Current Evidence and Outstanding Questions. Endocrine Reviews, 40(4), 1109–1151.

Płudowski, P., Holick, M.F., Grant, W.B., et al. (2018). Vitamin D supplementation guidelines. Journal of Steroid Biochemistry and Molecular Biology, 175, 125–135.

Roth, D.E., Abrams, S.A., Aloia, J., et al. (2018). Global prevalence and disease burden of vitamin D deficiency: a roadmap for action in low- and middle-income countries. Annals of the New York Academy of Sciences, 1430(1)