Because many vegetarians and vegans eat a high-oxalate diet, I have been interested to see if a prospective study might find a higher risk of kidney stones.
A recently released report from EPIC-Oxford measured the risk of being hospitalized for a kidney stone over the course of five years for people in various diet groups (1). Vegetarians (including vegans) had a 31% lower risk (.69, .48–0.98) as compared to high meat-eaters.
The other diet groups were:
Moderate meat-eaters, 50–99 g of meat per day – 0.80 (.57–1.11)
Low meat-eaters, < 50 g of meat per day – 0.52 (.35–0.80)
Fish-eaters – .73 (.48–1.11)
Oxalate intake was not measured.
I have updated Oxalate at VeganHealth.org with this info.
The authors also found a correlation between zinc intake and kidney stones. However, this finding barely reached statistical significance and the rate of kidney stones were very low in this population (.6% over five years). Kidney stones were not a common enough side effect in the recent Cochrane Database Analysis of clinical trials on zinc to be mentioned in their report.
Considering all of this, I am not worried that a modest zinc supplement will lead to a kidney stone.
1. Turney BW, Appleby PN, Reynard JM, Noble JG, Key TJ, Allen NE. Diet and risk of kidney stones in the Oxford cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC). Eur J Epidemiol. 2014 Apr 22. [Epub ahead of print] | link