Can You Take Zinc and Magnesium Together? Doses, Timing, ZMA

Yes. You can take zinc and magnesium together: the study that found zinc lowering magnesium absorption gave 142 mg of zinc a day, far above the NHS 25 mg line, and the pair sits in one tablet in many products. The UK amounts (how much zinc a day) are 9.5 mg of zinc a day for men and 7 mg for women, and 300 mg of magnesium for men and 270 mg for women; the NHS adds "Do not take more than 25mg of zinc supplements a day unless advised to by a doctor" and that "Having 400mg or less a day of magnesium from supplements is unlikely to cause any harm."¹ The Wellgard zinc guide and the vitamins and minerals guide have the rest.

Sources checked on 30 October 2026.

Can you take zinc and magnesium together?

Yes. Zinc's interaction evidence concerns iron, which can lower zinc absorption "if given together in a supplement" but not "in a meal as fortificants", and calcium, where the older meal studies point both ways.^{2, 11} For magnesium, the one metabolic study gave 142 mg of zinc a day and found lower magnesium absorption; at ordinary doses no trial was found, so the spacing some guides suggest (what should you not take with magnesium) is a precaution, not a trial result.³ Zinc on an empty stomach can cause nausea: in a six-week trial of 150 mg a day, symptoms were reported by 84% of women and 18% of men, so a combined tablet goes with food.^{4, 14} Of high doses the NHS warns: "Taking high doses of zinc reduces the amount of copper the body can absorb. This can lead to anaemia and weakening of the bones."¹ Anyone with kidney disease should not take magnesium without medical advice; in pregnancy and breastfeeding both minerals stay within the NHS amounts, and children have them only on a GP's advice.

What are zinc and magnesium each good for?

Each has its own authorised wordings in the Great Britain register, and none exists for the pair.⁵ Zinc contributes to the normal function of the immune system, to the maintenance of normal skin, hair, nails, bones and vision, to normal cognitive function, to normal fertility and reproduction, to the maintenance of normal testosterone levels in the blood and to the protection of cells from oxidative stress. Magnesium contributes to normal muscle function, to normal functioning of the nervous system, to normal psychological function, to normal energy-yielding metabolism, to the maintenance of normal bones and to a reduction of tiredness and fatigue. Neither list includes sleep, and only zinc's includes testosterone. Signs of zinc deficiency and the signs of low magnesium cover who runs short.

What is the best time to take zinc and magnesium?

No trial we found compares morning with evening for either mineral. Zinc goes with a meal to avoid nausea.^{4, 14} Magnesium is often taken with the evening meal, and more than 400 mg in a day can cause diarrhoea.¹ Both need a gap from a short list of medicines (what should you not take with zinc); when is the best time to take zinc and when to take magnesium set out the food and spacing rules.

Should you take zinc and magnesium before bed, and do they help you sleep?

Reports of better sleep on the pair at night are accounts, not trials. For zinc, a 2024 systematic review found eight randomised trials of 10 to 30 mg of zinc a day, or 50 mg every third day, for 4 to 48 weeks: most reported better sleep quality in adults, zinc "did not have a significant effect on sleep disorders", and the reviewers found "no consensus".⁶ The best-known trial gave 43 care-home residents with insomnia, average age 78, a nightly mix of 5 mg melatonin, 225 mg magnesium and 11.25 mg zinc for eight weeks; their sleep-quality score improved by 6.8 points more than placebo (95% CI 5.4 to 8.3), a result that cannot be attributed to the zinc or the magnesium, and melatonin in the UK is "available on prescription only".^{7, 8} For magnesium alone, a 2021 meta-analysis pooled three trials in 151 older adults with insomnia: they fell asleep 17.36 minutes sooner than on placebo (95% CI 7.44 to 27.27 minutes), total sleep time rose by 16.06 minutes without reaching significance, every trial was at moderate to high risk of bias, and the evidence was graded low to very low quality.⁹ Magnesium contributes to normal psychological function and normal functioning of the nervous system; those three trials are its placebo-controlled sleep evidence. Does magnesium help you sleep, does zinc help you sleep and which vitamin deficiency affects sleep have the detail.

What is ZMA, and what did its trials find?

ZMA is zinc, magnesium and vitamin B6, sold mainly to gym-goers. In a supplier-funded 2004 placebo-controlled trial, 42 resistance-trained men took ZMA or placebo before sleep through eight weeks of training: serum zinc rose by 11 to 17%, which was not significant, and there were no significant differences between the groups in anabolic or catabolic hormones, body composition, strength or muscular endurance.¹⁰ The zinc-only testosterone studies had no placebo group and are set out on what does zinc do for men; this ZMA trial is the placebo-controlled test, and it found no hormone change.¹⁰ The register sentence, "Zinc contributes to the maintenance of normal testosterone levels in the blood", belongs to zinc alone; magnesium has no testosterone wording, and vitamin B6 contributes to the regulation of hormonal activity.⁵ Keep zinc within the NHS 25 mg line and magnesium within 400 mg across every product.¹

What about calcium or vitamin D with zinc and magnesium?

Calcium, magnesium and zinc are sold as a trio, and the only rule is to count the zinc. The calcium-zinc evidence is mixed: in a 1980 tracer study, adding calcium as milk products improved zinc absorption from a wholemeal-bread meal.¹¹ The two-hour gap suggested on do you need a calcium supplement is a precaution, not a trial finding. Vitamin D has no documented interaction with zinc or magnesium in the NHS pages, and the three are commonly combined (what you should not take with vitamin D has its list); the NHS says 10 micrograms a day "will be enough for most people" and "Do not take more than 100 micrograms (4,000 IU) of vitamin D a day as it could be harmful."¹²

What we don't know

Whether zinc at supplement doses affects magnesium absorption: the only human study used 142 mg a day.³ Whether either mineral helps sleep in adults who are not short of it: the zinc trials reached no consensus and the magnesium trials were three small ones in older adults with insomnia.^{6, 9}

Frequently asked questions

Do you need zinc to absorb magnesium?

No. Each is absorbed on its own; we found no study showing one is needed for the other.

Can you take magnesium glycinate and zinc picolinate together?

Yes. The form changes the weight of the compound, not the rule: read the elemental figures on each label and keep the zinc within 25 mg a day.¹ Which magnesium is best compares the magnesium forms.

Which foods give both zinc and magnesium?

Seeds, nuts and wholegrains. In the UK food tables, pumpkin seeds carry 270 mg of magnesium and 6.6 mg of zinc per 100 g, so a 30 g handful gives about 81 mg and 2 mg; plain cashews carry 270 mg and 5.9 mg per 100 g, so 30 g gives about 81 mg and 1.8 mg.¹³ What foods contain magnesium has the full table.

What happens if you take zinc and magnesium every day?

Within the NHS lines, nothing the trials have measured. Above 400 mg of magnesium in a day, diarrhoea is likely; at high zinc doses (50 mg a day in the UK expert group's studies) copper absorption falls, which the NHS links to anaemia and weakening of the bones.^{1, 14}

Sources

1. NHS. Vitamins and minerals: others (zinc and magnesium). Page last reviewed 3 August 2020 (review overdue). nhs.uk.
2. Lönnerdal B. Dietary factors influencing zinc absorption. Journal of Nutrition, 2000. Narrative review; funding not stated on PubMed. PubMed 10801947.
3. Spencer H, Norris C, Williams D. Inhibitory effects of zinc on magnesium balance and magnesium absorption in man. Journal of the American College of Nutrition, 1994. Metabolic balance study, adult men; US government funding. PubMed 7836627.
4. Samman S, Roberts DC. The effect of zinc supplements on plasma zinc and copper levels and the reported symptoms in healthy volunteers. Medical Journal of Australia, 1987. Double-blind crossover trial, 47 adults, 6 weeks; public or charity funding listed on PubMed. PubMed 3547053.
5. Department of Health and Social Care. Great Britain nutrition and health claims (NHC) register. Register of authorised wordings. gov.uk.
6. Jazinaki MS, et al. Effects of zinc supplementation on sleep quality in humans. Health Science Reports, 2024. Systematic review, 8 randomised trials; no conflicts declared. PubMed 39377022.
7. Rondanelli M, et al. The effect of melatonin, magnesium, and zinc on primary insomnia in long-term care facility residents in Italy. Journal of the American Geriatrics Society, 2011. Randomised placebo-controlled trial, 43 care-home residents, 8 weeks; funding not stated on PubMed. PubMed 21226679.
8. NHS. About melatonin. Page last reviewed 13 February 2023 (review overdue). nhs.uk.
9. Mah J, Pitre T. Oral magnesium supplementation for insomnia in older adults. BMC Complementary Medicine and Therapies, 2021. Meta-analysis, 3 randomised trials, 151 older adults; no conflicts declared. PubMed 33865376.
10. Wilborn CD, et al. Effects of zinc magnesium aspartate (ZMA) supplementation on training adaptations and markers of anabolism and catabolism. Journal of the International Society of Sports Nutrition, 2004. Randomised placebo-controlled trial, 42 men, 8 weeks; supplement-company funded. PubMed 18500945.
11. Sandström B, et al. Zinc absorption from composite meals. I. The significance of wheat extraction rate, zinc, calcium, and protein content in meals based on bread. American Journal of Clinical Nutrition, 1980. Radioisotope meal study; funding not stated on PubMed. PubMed 7361691.
12. NHS. Vitamin D. Page last reviewed 3 August 2020 (review overdue). nhs.uk.
13. Public Health England. McCance and Widdowson's Composition of Foods Integrated Dataset (CoFID), 2021. Food composition dataset. gov.uk.
14. Expert Group on Vitamins and Minerals. Safe Upper Levels for Vitamins and Minerals, 2003: zinc. Expert committee report. UK Government Web Archive.

Spotted something out of date? Email support@wellgard.co.uk with the page address and the sentence.

This article is general information, not medical advice. Anyone on regular medicines or with kidney disease should ask a pharmacist or GP before adding either mineral.