Zinc intake and first kidney stones in teenagers
What it found
Teenagers with a first calcium kidney stone ate less zinc per day (8.1 mg) than healthy teenagers (10 mg).
The study cannot prove that low zinc caused the stones.
What they found
Studies in people
Zinc intake lower in cases
Teenagers with a first calcium stone ate an average of 8.1 mg of zinc per day, compared with 10 mg in the healthy group. This difference was statistically significant.
Zinc below recommended levels
Boys and girls with stones ate 2 mg and 1.2 mg less zinc per day, respectively, than the recommended daily intake for their age and sex.
Higher zinc, lower stone odds
Each extra 1 mg of daily zinc was linked to 13% lower odds of having a calcium stone. Those with zinc intake at the 75th percentile had 58% lower odds than those at the 25th percentile.
Urine zinc and diet
For every 1 mg more zinc eaten per day, urine zinc rose by an estimated 4.5 μg/dL. There was weak evidence that this rise was smaller in teenagers with stones than in healthy teenagers.
Phytate and oxalate
Higher daily phytate was linked to lower odds of stones, but this link disappeared after excluding one control with very high oxalate intake. Higher oxalate was also linked to lower odds, but the authors say this is likely spurious.
What the authors conclude
“Decreased dietary zinc intake was independently associated with incident calcium nephrolithiasis in this population of adolescents.”
Also in their conclusions
- They conclude that insufficient dietary zinc intake was independently associated with incident calcium kidney stone disease in this group of adolescents.
- They suggest that insufficient zinc intake may be a risk factor for developing calcium stones during childhood.
- They call for further mechanistic studies to understand how dietary zinc affects calcium stone formation.
How it was done
The authors wanted to find out whether trace minerals like zinc play a role in kidney stones in children, since little research has been done in this age group and stone cases are rising.
They compared 30 adolescents aged 12 to 18 with a first calcium kidney stone and 30 healthy adolescents matched for age, sex, race and month of enrollment. Each participant completed three 24-hour dietary recalls and gave a spot urine sample.
What it can’t tell you
- This was a case-control study, so it can show a link but cannot prove that low zinc causes kidney stones.
- The study cannot show whether changing zinc intake would prevent stones.
- It did not assess zinc supplements, and it used spot urine rather than 24-hour urine collections.
Who paid
- Funding
- Funded by NIDDK NIH HHS (from the PubMed record).
- Authors work at
- Children's Hospital of Philadelphia, Pennsylvania; Perelman School of Medicine at the University of Pennsylvania, Pennsylvania; University of California, San Francisco
The paper
- Title
- Dietary Zinc and Incident Calcium Kidney Stones in Adolescence
- Type
- Study
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Tasian GE, Ross ME, Song L, et al (2017). Dietary Zinc and Incident Calcium Kidney Stones in Adolescence. The Journal of urology. doi:10.1016/j.juro.2016.11.096Free full textPubMed 27889417DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error