Link between Vitamin D and prostate cancer

http://www.harvardprostateknowledge.org/low-vitamin-d-tied-aggressive-prostate-cancer

https://www.vitamindcouncil.org/health-conditions/prostate-cancer/

https://www.sciencedaily.com/releases/2015/03/150322080155.htm

when men with low-grade prostate cancer took vitamin D supplements for a year, 55 percent of them showed decreased Gleason scores or even complete disappearance of their tumors compared to their biopsies a year before (J. Clin. Endocrinol. Metab., 2012, DOI: 10.1210/jc.2012-1451). – SOURCE

http://www.webmd.com/prostate-cancer/news/20160302/low-vitamin-d-levels-may-signal-more-aggressive-prostate-cancer#1
Compared with white men, Blacks have a higher incidence of prostate cancer. Comparatively, their disease is more aggressive, which leads to higher mortality rates. Hollis noted that Black men also exhibit a high prevalence for vitamin D deficiency. [Source]

https://www.healthafter50.com/prostate/article/aggressive-prostate-cancer-and-low-vitamin-d

http://www.albany.edu/news/13412.php

http://militarymedicine.amsus.org/doi/pdf/10.7205/MILMED-D-12-00540
“veterans who were initially vitamin D deficient were significantly less likely to survive than those who were not initially deficient” – source

http://www.drmagaziner.com/vitamin-d-deficiency-increased-risk-prostate-cancer/