Deficiency may be treated with 2–8 mg/day elemental copper for weeks to months under care while addressing the cause
Reviewed · Published
Copper
Required for iron metabolism, connective tissue, and antioxidant enzymes.
Established functions
- Required for iron metabolism, connective tissue, and antioxidant enzymes.
Dietary sources
- liver
- oysters
- cashews
Claims and evidence
Claims that Copper alone prevents or treats disease, or invariably improves health without deficiency, are unsupported.
Japanese reference amounts
- Japanese adults (age and sex as specified): Adults: 0.7 mg/day (RDA)
Amounts studied
- Deficiency may be treated with 2–8 mg/day elemental copper for weeks to months under care while addressing the cause
Tolerable upper limits
- Adults: 7 mg/day
Forms and bioavailability
Supplement forms: copper gluconate, copper sulfate
- High-dose zinc inhibits intestinal copper absorption.
Safety and interactions
Adverse effects
- nausea
- abdominal pain
- liver injury
Medicine and nutrient interactions
- zinc, penicillamine
Contraindications and cautions
- Do not supplement with Wilson disease.
Practical selection
- Compare Copper amount per serving, form, allergens, and batch testing; prefer a single-ingredient product suited to the intended use.
Sources and review
- Dietary Reference Intakes for Japanese (2025)Ministry of Health, Labour and Welfare (Japan)
- NIH ODS mineral fact sheetsNIH Office of Dietary Supplements
Daiki Minaki (editorial and evidence review) ·