Which vitamin depletes copper?
The short answer
Vitamin C is the most notable one. High daily doses (generally above 1,500 mg) have been shown to reduce copper absorption and status over time. Zinc, while not a vitamin, has an even stronger depleting effect on copper at high doses and is the more common culprit behind copper deficiency in supplement users.
Vitamin C at high doses
Large amounts of vitamin C can interfere with copper absorption, likely by reducing copper to a form that is less readily taken up and by affecting ceruloplasmin. This is only a practical concern at sustained high supplemental doses — roughly 1,500 mg/day and above. The vitamin C in food and in typical multivitamins is not a problem.
Zinc is the bigger culprit
Although the question asks about vitamins, the mineral most responsible for copper depletion is zinc. Sustained high-dose zinc (commonly 50–100 mg/day in immune-support products) induces metallothionein in the gut, which preferentially traps copper and carries it out of the body. Over months this can cause a genuine copper deficiency. If you take high-dose zinc, read our article on copper and zinc balance.
Sources
- NIH Office of Dietary Supplements — Copper Fact Sheet for Health Professionals — ods.od.nih.gov
- Duncan et al. (2023). Iatrogenic copper deficiency. Br J Clin Pharmacol. — bpspubs.onlinelibrary.wiley.com
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