Quick answer
- The NHS says not to take more than 25 mg of zinc a day from supplements unless a doctor advises it, because high doses reduce copper absorption. Adults need about 9.5 mg (men) or 7 mg (women) a day, usually from food.
- EFSA's safe upper level is 25 mg a day from food and supplements together; Germany's BfR advises at most 6.5 mg per daily dose in a supplement.
- Long-term high zinc intake blocks copper absorption and can cause anaemia and low white blood cell counts.
- For colds, zinc may shorten them by about 2 days if started early, on low-certainty evidence. It does not prevent them.
- Well-absorbed forms include bisglycinate, picolinate, citrate and gluconate; compare the elemental zinc per dose.
Key numbers
- UK daily need (NHS)
- 9.5 mg men, 7 mg women
- UK maximum from supplements (NHS)
- 25 mg/day
- Unless a doctor advises more.
- Reference intake on labels (NRV)
- 10 mg/day
- Safe upper level (EFSA)
- 25 mg/day
- Food and supplements together.
- Germany (BfR guidance)
- 6.5 mg per daily dose
- Spain
- No national maximum
- Minimum for an authorised claim
- 1.5 mg per daily dose
What these terms mean: NRV upper levels (NHS, EFSA) maximum levels by country daily dose
How to choose
- Check the elemental zinc per daily dose, not the weight of the zinc compound.
- For daily use, 5–10 mg is plenty for most adults who eat a varied diet. Higher doses are for short periods or on medical advice.
- Count zinc from other products: multivitamins, "hair" formulas and immune blends often contain it too.
- Prefer bisglycinate, picolinate, citrate or gluconate; zinc oxide is cheaper but may be absorbed less well.
- Take zinc away from iron and calcium supplements and with food if it upsets your stomach.
Zinc forms compared
| Form | Typical use | Good to know |
|---|---|---|
| Bisglycinate | Tablets and capsules | Usually well tolerated |
| Picolinate | Capsules | Well absorbed; often pricier |
| Citrate | Tablets, effervescents | Well absorbed, mid price |
| Gluconate | Tablets, lozenges | Common in cold lozenges |
| Oxide | Cheap tablets, multivitamins | Most zinc per tablet; may be absorbed less well |
| Sulphate | Medicines, some supplements | Can upset the stomach |
Maximum zinc per day, by country
Most zinc tablets on sale give 15 to 25 mg. A 25 mg tablet is within the NHS figure, but above the binding limits in Belgium, Italy, France and Switzerland and almost four times Germany’s guidance. This is what each country allows per daily dose:
Limits are per recommended daily dose of a supplement, for adults; several countries set lower ones for children and teenagers. Inside the EU, a product lawfully sold in one country can usually be sold in another even above its limit (mutual recognition). All 7 nutrients and 13 countries →
What the evidence says
Most people in Europe get enough zinc from meat, dairy, wholegrains and legumes; vegetarians and vegans need somewhat more because plant phytates reduce absorption. Supplements help most when intake is genuinely low.
For colds, a 2024 Cochrane review found that zinc may shorten an existing cold by about two days, on low-certainty evidence, and showed no clear benefit for prevention. The bigger practical risk is the opposite: high-dose products taken for weeks. Read zinc and vitamin C for colds for the details.
What the label may legally claim
Authorised claims (GB and EU registers)
- Contributes to the normal function of the immune system
- Contributes to the maintenance of normal skin, hair, nails and bones
- Contributes to normal fertility and reproduction and normal testosterone levels in the blood
- Contributes to normal cognitive function, vision and protection of cells from oxidative stress (all from 1.5 mg per daily dose)
Not authorised in GB or the EU
- Preventing or curing colds
- Testosterone "booster"
- Hair growth
How health claims work (UK & EU): health claims
Products we have checked
Label data checked by NutriMetrics for products sold in Spain and Germany. UK product checks are next. Sorted alphabetically, not ranked.
| Product | Per daily dose | Sold in | Label |
|---|---|---|---|
| Solgar Zinc Picolinate 22 mg1 tablet a day with food | 22 mg · picolinate | Spain · Germany (not yet confirmed) | Source |
Who should be careful
- Long-term high doses (above 25 mg a day from all sources) can lead to copper deficiency. Don't keep taking high-dose "cold" products for weeks.
- Medicines: zinc can reduce the absorption of some antibiotics (quinolones, tetracyclines). Take them a few hours apart.
- Nausea is common when zinc is taken on an empty stomach.
FAQ
How much zinc should I take a day?
For most adults with a varied diet, 5–10 mg from a supplement is plenty. The NHS says not to take more than 25 mg a day from supplements unless a doctor advises it. EFSA's safe upper level is also 25 mg, from all sources, and Germany's BfR advises no more than 6.5 mg per daily dose.
Which zinc form is best?
Bisglycinate, picolinate, citrate and gluconate are all reasonable choices. Zinc oxide is cheaper but may be absorbed less well. The elemental zinc dose matters more than the name.
Does zinc help with colds?
A 2024 Cochrane review found zinc may shorten a cold by about two days if started early, but the evidence is low certainty, and zinc does not prevent colds.
Sources
- NHS — Others (magnesium, selenium, zinc)
- NHS — Common cold
- DHSC — Great Britain nutrition and health claims (NHC) register
- EFSA — Summary of tolerable upper intake levels (2024)
- BfR — Proposed maximum levels for zinc in food supplements
- Nault D et al. Zinc for prevention and treatment of the common cold. Cochrane Database Syst Rev, 2024
- NIH Office of Dietary Supplements — Zinc fact sheet for health professionals
- European Commission — EU Register of nutrition and health claims
Information only, not medical advice. No product on this page is a paid placement.