While I’m visiting the relationship between vitamin supplements and disease (e.g. “Conclusions: These Results Suggest That Multivitamin Use Is Associated With An Increased Risk Of Breast Cancer”), I thought I’d throw these two up:
1. Zinc Supplement Use And Risk Of Prostate Cancer, Journal of the National Cancer Institute, July 2003
We examined the association between supplemental zinc intake and prostate cancer risk among 46 974 U.S. men participating in the Health Professionals Follow-Up Study. During 14 years of follow-up from 1986 through 2000, 2901 new cases of prostate cancer were ascertained, of which 434 cases were diagnosed as advanced cancer.
Compared with nonusers, men who consumed more than 100 mg/day of supplemental zinc had a relative risk of advanced prostate cancer of 2.29, and men who took supplemental zinc for 10 or more years had a relative risk of 2.37.
Our findings, that chronic zinc oversupply may play a role in prostate carcinogenesis, warrant further investigation.
2. Zinc Intake And Risk Of Prostate Cancer: Case-Control Study And Meta-Analysis, PLoS One, November 2016
Using a dose-response meta-analysis, we observed a non-linear trend in the relationship between zinc intake and prostate cancer (p for nonlinearity = 0.0022).
14,000 micrograms is only 14 mg. The RDA for zinc for men is 11 mg. So, not much more than the RDA may be a problem.