Vitamin D is a vital regulatory hormone necessary for healthy human physiology. The official task of vitamin D is calcium homeostasis; however, vitamin D deficiency is related to both calcium-related conditions such as osteoporosis and rickets, and non-calcemia-related disorders such as autoimmune diseases, cardiovascular disease, diabetes, and breast, colon, and prostate cancer. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an Original Essay Prostate cancer is of particular concern because African American men are disproportionately affected by both vitamin D deficiency and prostate cancer risk. African Americans not only experience prostate cancer at an earlier age, but are 50% more likely to develop it and have double the mortality rate of European Americans. Skin pigmentation is the greatest predictor of vitamin D deficiency in the United States because UV-induced vitamin D synthesis is the dominant source of the active form of vitamin D and is inhibited by melanin. Therefore, more than 65% of African American men are deficient with serum levels less than 20 ng/ml and more than 90% have a vitamin D deficiency. Richards et. al. describes the first evaluation of prostatic axis and vitamin D in samples from a disparate cross-sectional group of subjects undergoing radical prostatectomy. Vitamin D metabolites were measured in both prostate tissue and serum. Gene expression patterns participating in vitamin D transport, metabolism, and vitamin D receptor were quantified in prostatic epithelial tissues. Please note: this is just a sample. Get a custom paper from our expert writers now. Get a Custom Essay The results show that African Americans were deficient in serum vitamin D and had increased amounts of the active form of vitamin D in prostate tissues. Vitamin D receptor mRNA levels were also found to be expressed higher in African Americans than in European Americans. More importantly, gene expression of Megalin, which binds and internalizes vitamin D together with its transporter protein, is significantly positively correlated with West African ancestry. This is of particular interest because Megalin also binds and internalizes sex hormone-binding globulin, which is the carrier protein for testosterone, the precursor to dihydrotestosterone; a known driver of prostate cancer.