Magnesium and Zinc Together: Can You Take Them at the Same Time?

Yes, you can take zinc and magnesium together, even at the same time: the NIH Office of Dietary Supplements (ODS) describes a zinc and magnesium interaction only at very high zinc doses, 142 mg a day from supplements, which is more than three times the 40 mg adult upper limit for zinc. Below: what each mineral does, adult needs, the spacing rules that do matter, food sources, forms, and how these minerals relate to vitamin D.

It is educational, not medical advice.

Key Takeaways

• Magnesium and zinc can be taken at the same time. The interaction ODS describes was seen at 142 mg of zinc a day.
• Adult RDAs: magnesium 400 to 420 mg for men and 310 to 320 mg for women; zinc 11 mg for men and 8 mg for women.
• The magnesium upper limit of 350 mg a day applies to supplements and medicines only. The zinc upper limit of 40 mg a day covers food and supplements together.
• The spacing that matters is from certain antibiotics, bisphosphonates, penicillamine and iron supplements of 25 mg or more, not from each other.
• Magnesium and boron both relate to how the body uses vitamin D, which is why they are often grouped with zinc as "vitamin D cofactors."

Can You Take Magnesium and Zinc Together?

Yes. Both ODS fact sheets mention the same single study on how the two minerals interact: very high doses of zinc from supplements, 142 mg a day, interfered with magnesium absorption and disrupted the body's magnesium balance (NIH ODS: Magnesium, 2026; NIH ODS: Zinc, 2026). The study behind that statement was published by Spencer and colleagues in 1994.

That dose is far above what most people take. The adult upper limit for zinc is 40 mg a day, and the RDA is 8 to 11 mg. Neither fact sheet tells you to separate magnesium and zinc at ordinary amounts.

Taking a Combined Zinc and Magnesium Supplement

Many products put zinc and magnesium in one capsule or tablet, sometimes with other nutrients. Because ODS describes interference only at 142 mg of zinc a day, there is no need to split them into separate products at ordinary amounts. What a combined product changes is the math. Read the Supplement Facts panel for the elemental amount of each mineral, then add the zinc from any multivitamin, zinc lozenges and fortified foods, and keep the total at or under 40 mg a day. Keep magnesium from supplements and medicines, including some antacids and laxatives, at or under 350 mg a day (NIH ODS: Magnesium). Our upcoming Vitamin D Cofactor Capsules, for example, provide 100 mg of magnesium and 10 mg of zinc per 2 capsules, within both limits.

What Magnesium and Zinc Do

Magnesium is a cofactor in more than 300 enzyme systems that regulate diverse biochemical reactions in the body, including protein synthesis, muscle and nerve function, blood glucose control and blood pressure regulation (NIH ODS: Magnesium, 2026).

Zinc is required for the catalytic activity of hundreds of enzymes. ODS lists roles in immune function, protein and DNA synthesis, wound repair, and cell signaling and division (NIH ODS: Zinc, 2026). ODS also reports that 15% of U.S. adults have zinc intakes below the Estimated Average Requirement. For more on what zinc does, see our guide to zinc benefits, and for women, see zinc for women.

How Much Magnesium and Zinc Do Adults Need?

The table shows the adult Recommended Dietary Allowances (RDAs) and Tolerable Upper Intake Levels (ULs) from ODS, plus what our upcoming Vitamin D Cofactor Capsules provide. Boron is included because it is the third mineral in that formula.

Mineral	Adult RDA, men	Adult RDA, women	Adult upper limit	Our capsules, per 2 capsules
Magnesium	400 mg (19 to 30); 420 mg (31 and older)	310 mg (19 to 30); 320 mg (31 and older)	350 mg a day from supplements and medicines only	100 mg (as magnesium bisglycinate)
Zinc	11 mg	8 mg	40 mg a day from food and supplements	10 mg (as zinc bisglycinate)
Boron	No RDA set	No RDA set	20 mg a day	3 mg (as boron glycinate)

Sources: NIH ODS: Magnesium, NIH ODS: Zinc, NIH ODS: Boron. RDAs are higher during pregnancy and lactation; check the fact sheets for those values.

Two details matter here. The magnesium UL counts only magnesium from supplements and medicines, not the magnesium found naturally in food and drinks. The zinc UL counts everything, so add up zinc from a multivitamin, a separate zinc product and fortified foods. ODS notes the zinc UL does not apply to people receiving zinc for medical treatment.

Timing and Spacing Tips

ODS does not name a best time of day for either mineral. The spacing guidance it does give is about other things you take:

• Tetracycline and quinolone antibiotics. Both minerals can bind these antibiotics. Take the antibiotic at least 2 hours before or 4 to 6 hours after a magnesium or zinc supplement (NIH ODS: Magnesium; NIH ODS: Zinc).
• Bisphosphonates. Take magnesium rich supplements or medicines at least 2 hours before or after oral bisphosphonates such as alendronate.
• Penicillamine. Take zinc supplements and penicillamine at least 1 hour apart.
• Iron supplements. Taking supplements with 25 mg or more of elemental iron at the same time as zinc can reduce zinc absorption. ODS adds that the iron in enriched or fortified foods does not significantly interfere.
• Diuretics and acid reducers. Loop and thiazide diuretics can increase magnesium loss, thiazide diuretics increase zinc loss in urine, and long term proton pump inhibitor use (typically more than a year) can lower magnesium. Talk with your prescriber rather than changing a medicine yourself.

If none of these apply, the practical rule is consistency: take your minerals at a time you will remember. If you prefer the evening, our guide to magnesium glycinate for sleep covers that routine.

Food Sources of Magnesium and Zinc

Pumpkin seeds show up on both lists: 1 ounce of roasted pumpkin seeds has 156 mg of magnesium and 2.2 mg of zinc, per the ODS tables.

• Magnesium (per serving): pumpkin seeds, roasted, 1 oz, 156 mg; chia seeds, 1 oz, 111 mg; almonds, dry roasted, 1 oz, 80 mg; spinach, boiled, half cup, 78 mg; cashews, dry roasted, 1 oz, 74 mg; peanuts, oil roasted, quarter cup, 63 mg; black beans, cooked, half cup, 60 mg.
• Zinc (per 3 oz unless noted): farmed Eastern oysters, raw, 32 mg; beef bottom sirloin, roasted, 3.8 mg; blue crab, cooked, 3.2 mg; pumpkin seeds, roasted, 1 oz, 2.2 mg.

Phytates in whole grains and legumes bind zinc in the gut and reduce how much is absorbed, which is one reason ODS says people who follow vegetarian or vegan diets might benefit from zinc supplements (NIH ODS: Zinc).

For a longer list with milligrams per serving, see foods high in magnesium, and for zinc amounts by age, see how much zinc per day.

For zinc on its own, our guide to foods high in zinc ranks 26 foods by zinc per serving and includes a vegan sample day.

Which Forms to Choose

Labels list the amount of elemental mineral, not the weight of the whole compound, so 10 mg of zinc means 10 mg of zinc itself. On absorption, ODS reports that forms of magnesium that dissolve well in liquid are absorbed better, and that the aspartate, citrate, lactate and chloride forms tend to have higher bioavailability than magnesium oxide. For zinc, it reports absorption of about 61% for zinc citrate and zinc gluconate in young adults and 50% for zinc oxide.

We compare the chelated forms in separate guides rather than repeat them here: see magnesium bisglycinate vs glycinate, zinc picolinate vs bisglycinate vs gluconate and our zinc bisglycinate ingredient page.

Magnesium, Zinc, Boron and Vitamin D: What Are Vitamin D Cofactors?

"Vitamin D cofactors" is an informal name for nutrients involved in how the body activates and uses vitamin D. Magnesium, zinc and boron are the three minerals most often grouped this way. Here is what the sources we can cite say:

• Magnesium. ODS says magnesium affects the concentrations of both parathyroid hormone and the active form of vitamin D (NIH ODS: Magnesium). A review notes that all of the enzymes that metabolize vitamin D seem to require magnesium as a cofactor (Uwitonze and Razzaque, 2018). In a randomized, double blind trial of 180 adults aged 40 to 85, magnesium raised blood 25(OH)D3 in people who started close to 30 ng/mL and lowered it in people who started higher; the authors concluded that good magnesium status may be important for optimizing vitamin D status (Dai et al., 2018).
• Boron. A 2015 review describes boron as important for the body's use of vitamin D, estrogen and testosterone, and for boosting magnesium absorption (Pizzorno, 2015). ODS reports that low boron intakes appear to reduce plasma calcium and serum 25-hydroxyvitamin D levels (NIH ODS: Boron).
• Zinc. Zinc is the third mineral in most cofactor formulas. It is an essential mineral required for hundreds of enzymes, and the zinc RDA and upper limit above apply whether or not you take vitamin D.

For more on each piece, read vitamin D and magnesium, boron benefits, vitamin D3 and K2 and our vitamin D3 ingredient page. For adding boron to magnesium and zinc, see our guide to magnesium, zinc and boron.

Coming Soon From Synchronicity

Our Vitamin D Cofactor Capsules will have magnesium 100 mg (as magnesium bisglycinate), zinc 10 mg (as zinc bisglycinate) and boron 3 mg (as boron glycinate) in every 2 capsules. They are made to pair with our Vitamin D3 + K2 Drops, available now, with vegan vitamin D3 from lichen and vitamin K2 as MK-4 and MK-7. The capsules are not on sale yet. Pre-order on the product page to join the waitlist; no payment is taken. Our guide to vitamin K2: MK-4 vs MK-7 explains how those two forms differ.

Safety Note

High doses of magnesium from supplements or medicines can cause diarrhea, nausea and abdominal cramping. Too much zinc can cause nausea, dizziness, headaches, gastric distress, vomiting and loss of appetite, and doses of 50 mg of zinc or more over a period of weeks can inhibit copper absorption (NIH ODS: Magnesium; NIH ODS: Zinc). Stay within the upper limits unless a clinician advises otherwise. If you have kidney problems, take prescription medicine, or are pregnant or breastfeeding, check with a healthcare provider before adding minerals. See magnesium glycinate side effects for more.

Frequently Asked Questions

Can you take magnesium and zinc together?

Yes. ODS describes interference only at 142 mg of zinc a day from supplements, far above the 40 mg adult upper limit.

Should zinc and magnesium be taken separately?

Not at ordinary doses. The spacing ODS recommends is from tetracycline and quinolone antibiotics, bisphosphonates (for magnesium), penicillamine (for zinc) and iron supplements of 25 mg or more (for zinc).

Can I take zinc and magnesium at night?

Yes. ODS does not set a best time of day for either mineral, so night works if that is when you will take them consistently, as long as you keep any spacing from the medicines listed above.

What are vitamin D cofactors?

An informal term for nutrients involved in how the body uses vitamin D. Magnesium affects the active form of vitamin D, and low boron intake appeared to lower 25-hydroxyvitamin D levels. Zinc usually completes the trio in cofactor formulas.

How much magnesium and zinc should I take a day?

The adult RDA is 310 to 420 mg of magnesium and 8 to 11 mg of zinc, from food and supplements combined. Keep supplemental magnesium at or under 350 mg and total zinc at or under 40 mg unless a clinician advises otherwise.

Does zinc lower copper?

At high doses, yes. ODS says doses of 50 mg of zinc or more over a period of weeks can inhibit copper absorption.

Can I take magnesium and zinc with vitamin D?

Yes. Magnesium and boron both relate to how the body uses vitamin D, which is why cofactor formulas pair them with vitamin D products.

Does zinc interfere with magnesium?

Only at very high doses. The NIH ODS magnesium and zinc fact sheets cite one study in which 142 mg of zinc a day from supplements interfered with magnesium absorption and disrupted the body's magnesium balance (Spencer and colleagues, 1994). That is more than three times the 40 mg adult upper limit for zinc and more than 12 times the 11 mg RDA for men. At ordinary amounts, ODS does not advise separating the two.

Does magnesium block zinc absorption?

The ODS fact sheets do not list magnesium as something that lowers zinc absorption. The interaction they describe runs the other way, from very high zinc doses to magnesium. What ODS says can reduce zinc absorption is iron supplements of 25 mg or more taken at the same time as zinc, and phytates in whole grains and legumes.

Can I take zinc and magnesium with an iron supplement?

Zinc is the one to watch. ODS says supplements with 25 mg or more of elemental iron taken at the same time as zinc can reduce zinc absorption, while the iron in enriched or fortified foods does not significantly interfere. If you take an iron supplement, take it at a different time of day from your zinc. If you take iron for a diagnosed deficiency, ask your clinician how to time it.

Sources

1. NIH Office of Dietary Supplements. Magnesium: Fact Sheet for Health Professionals. Updated January 6, 2026. ods.od.nih.gov
2. NIH Office of Dietary Supplements. Zinc: Fact Sheet for Health Professionals. Updated January 6, 2026. ods.od.nih.gov
3. NIH Office of Dietary Supplements. Boron: Fact Sheet for Health Professionals. Updated June 9, 2022. ods.od.nih.gov
4. Uwitonze and Razzaque. Review of magnesium and vitamin D metabolism. 2018. doi:10.7556/jaoa.2018.037
5. Dai and colleagues. Randomized, double blind trial of magnesium and vitamin D status in 180 adults. 2018. doi:10.1093/ajcn/nqy274
6. Pizzorno L. Nothing boring about boron. Integr Med (Encinitas). 2015. PMID 26770156. pubmed.ncbi.nlm.nih.gov/26770156

These statements have not been evaluated by the Food and Drug Administration. This content is for education and is not medical advice. Our products are not intended to diagnose, treat, cure or prevent any disease. Talk with a healthcare provider before starting a new supplement if you are pregnant, breastfeeding or taking medication.