A Northwestern University study of 190 men of median age 64 having their prostate removed found those with low vitamin D levels were more likely to have rapidly growing tumors than those with normal levels of the “sunshine” vitamin. The study was published on-line in the Journal of Clinical Oncology. The researchers found that nearly 46 percent of the men had aggressive cancer, and these men had vitamin D levels about 16 percent lower than men with slower-growing tumors. Racial distinctions were also noted in this study with black men having more aggressive tumors and lower vitamin D levels than white men. After accounting for age, PSA levels and abnormal rectal exams, researchers found that blood vitamin D levels below 30 nanograms per milliliter (ng/mL) were linked to higher odds of aggressive prostate cancer. The study however does not necessarily prove that vitamin D deficiency causes aggressive prostate cancer, only that the two are associated. Experts quoted herein state that while these results are important enough to spur further study into the vitamin D – prostate cancer potential biomarker connection, there is not sufficient evidence at this time to recommend vitamin D supplements to prevent prostate cancer or to make it less aggressive. It should be noted however that most Americans in general have lower than normal vitamin D levels which seem to be implicated in several medical conditions. It is recommended that men and women be blood-tested routinely for vitamin D levels using the 25-hydroxy vitamin D assay. Optimum levels should be at least 30 ng/mL. (One can get too much vitamin D so consult your physician to discuss test results and supplement recommendations if needed.) It was also suggested that perhaps men should be tested for Vitamin D when they are diagnosed with prostate cancer and subsequently supplemented with vitamin D if they are deficient. For further information, see the link to this study published in the National Institutes of Health Medline. For an additional summary of this study see the following link from Cancer Therapy Advisor.