Health Reference LibraryCan you take zinc and iron together?
This entry is part of the Nutri Tailor Health Reference Library — cited research on supplements, nutrients and adjacent areas of health.
Summary
Yes. For most people, taken with food at ordinary doses, zinc and iron do not get in each other’s way. The clash is real but narrow: in the 1991 study, a zinc dose five times the iron dose in plain water cut iron absorption by 56 percent, and the same pair in a meal showed no effect at all. A 2012 study found that leaving 30 to 60 minutes between them removed the interaction even without food. So the rule is for people taking high doses of both, usually while correcting a deficiency: separate them by one to two hours. Multivitamin level doses with breakfast need no spacing.
How it works
Iron and zinc use the same transporter at the gut wall when they arrive as free ions in solution, and the one present in greater amount wins. Food changes that. Proteins, fibre and organic acids in a meal bind the minerals loosely and hand them over more slowly, which is why the effect seen in water disappears in a meal. The wider lesson from the 2010 review is that single meal isotope studies exaggerate what happens over a whole diet. Iron in the 15 mg range and zinc in the 8 to 15 mg range with food is inside the safe zone.
Effective dose
Reference intakes: iron 8.7 mg a day for men and 14.8 mg for women aged 19 to 50; zinc 9.5 mg for men and 7 mg for women. The interaction becomes worth planning around when someone is correcting iron deficiency at 30 to 65 mg of iron a day from a GP and taking a separate zinc supplement above 15 mg. At those doses, keep them apart.
Timing
A simple schedule for supplement doses of both: iron mid morning with water or a light meal, zinc with dinner. Keep tea and coffee an hour clear of the iron, and calcium supplements two hours clear. If you only take one of the two above reference intake, no schedule is needed.
Safety profile
Do not take iron without a blood test that shows you need it. Zinc above 25 mg a day for months lowers copper and needs copper alongside. Both can cause nausea on an empty stomach; iron bisglycinate and zinc picolinate are the gentler forms.
Interactions
Iron is inhibited by calcium, tea and coffee; helped by vitamin C at the same meal. Zinc is inhibited by phytates in whole grains and reduces copper at high doses. Neither is affected by the other at ordinary doses with food.
| Interaction | Issue | Guidance | Citation |
|---|---|---|---|
| Iron and zinc | Bidirectional, dose-ratio dependent inhibition | Separate iron and zinc supplements by around 1-2 hours | NIH ODS — Iron Fact Sheet for Health Professionals |
| Iron and calcium | Calcium reduces non-haem iron absorption | Separate iron supplements from calcium-containing meals by around 2 hours | NIH ODS — Iron Fact Sheet for Health Professionals |
| Iron and manganese | Manganese reduces iron absorption | Separate iron from manganese-containing supplements by around 1-2 hours | NIH ODS — Iron Fact Sheet for Health Professionals |
Guideline positions
Iron absorption and the effect of zinc in solution versus a meal, isotope study (1991). Zinc and iron interaction and the effect of spacing doses (2012). Review of the influence of dietary factors on mineral absorption (2010). NHS reference intakes for iron and zinc.
Practical framework
Correcting a deficiency: space them. Everyday doses: take them together with a meal. Nutri Tailor stocks [iron bisglycinate with vitamin C](/products/iron-vitamin-c), 15 mg of iron per capsule, and [zinc picolinate](/products/zinc), 13.8 mg of zinc per capsule, as separate products, which makes any spacing easy to keep, both made in the UK. To read your own result against the UK ranges, use the free blood test result interpreter. This is a summary of published research, not personal health advice. Talk to your GP or a registered nutritional therapist before changing what you take, especially if you are pregnant, have a diagnosed condition or are under ongoing care.
Common misconceptions
That zinc and iron cancel each other out: only in water at high doses. That a multivitamin with both is pointless: the doses are small and taken with food. That you need a four hour gap: 30 to 60 minutes removed the effect in the 2012 study, and one to two hours is a comfortable margin.
Who this matters for
This entry is relevant for the following groups and situations:
- Pregnancy
- Breastfeeding
- Children
- Inflammatory bowel disease
- Adults over 65
Recent updates
Reviewed and corrected against sources on , ,
Sources
- Rossander-Hultén L, Brune M, Sandström B, Lönnerdal B, Hallberg L 1991. Competitive inhibition of iron absorption by manganese and zinc in humans. American Journal of Clinical Nutrition. PMID: 2058577 · DOI: 10.1093/ajcn/54.1.152
- Sandström B, Davidsson L, Cederblad Å, Lönnerdal B 1985. Oral iron, dietary ligands and zinc absorption. Journal of Nutrition. PMID: 3973750 · DOI: 10.1093/jn/115.3.411
- Olivares M, Pizarro F, Ruz M 2007. Zinc inhibits nonheme iron bioavailability in humans. Biological Trace Element Research. PMID: 17873388 · DOI: 10.1007/BF02698079
- Olivares M, Pizarro F, Ruz M, López de Romaña D 2012. Acute inhibition of iron bioavailability by zinc: studies in humans. Biometals. PMID: 22297381 · DOI: 10.1007/s10534-012-9524-z
- Hurrell R, Egli I 2010. Iron bioavailability and dietary reference values. American Journal of Clinical Nutrition. PMID: 20200263 · DOI: 10.3945/ajcn.2010.28674f
- Snook J, Bhala N, Beales ILP, Cannings D, Kightley C, Logan RPH, Pritchard DM, Sidhu R, Surgenor S, Thomas W, Verma AM 2021. British Society of Gastroenterology guidelines for the management of iron deficiency anaemia in adults. Gut. PMID: 34497146 · DOI: 10.1136/gutjnl-2021-325210
- NIH Office of Dietary Supplements. NIH Office of Dietary Supplements — Iron Fact Sheet for Health Professionals. NIH Office of Dietary Supplements (US government).