AIMS: We aimed to determine whether there is an association between dietary zinc 
intake (DZI) and prevalent kidney stone disease defined as self-report of any 
previous episode of kidney stone.
METHODS: We examined The Third National Health and Nutrition Examination Survey 
(NHANES III), a large US population-based cross-sectional study, and used 
logistic regression analyses to determine the independent association between 
DZI and prevalent kidney stone disease.
RESULTS: A total of 15,444 men and women over 18 years of age were eligible for 
analysis. Among them, 710 participants reported a history of kidney stones. 
Stone formers tended to have higher DZI than non-stone formers among NHANES III 
participants, though this difference did not reach statistical significance (p = 
0.1). Multivariate adjusted logistic regression analysis revealed that higher 
DZI (log transformed) was associated with a significantly increased risk of 
kidney stone disease (odds ratio, OR = 1.41, 95% confidence interval, CI: 
1.10-1.81, p = 0.01). After categorizing zinc intake into three groups, those 
with highest DZI (>15 mg/day) were also associated with a significantly 
increased risk of kidney stone disease, compared to those with lower DZI (<7 
mg/day; OR = 1.70, 95% CI: 1.13-2.57, p = 0.01).
CONCLUSIONS: Our study suggests that higher DZI is associated with increased 
risk of kidney stone disease. Future prospective studies are needed to clarify 
the causal relationship between zinc intake and kidney stone formation.