Zinc: what to pair and what to space apart

Zinc pairs well with magnesium and B6 (the classic ZMA stack), Vitamin C (quercetin and Vitamin C combinations are popular immune stacks), and small amounts of copper (1 to 2 mg copper bisglycinate to offset depletion at doses above 25 mg zinc). Zinc antagonises iron and calcium, space these by at least 2 hours. Drug interactions include tetracycline and quinolone antibiotics (zinc reduces their absorption, space by 2 hours), penicillamine, and bisphosphonates. PPIs and H2 blockers reduce zinc absorption modestly over months. Zinc lozenges (gluconate or acetate) at 75 mg per day in divided doses for up to a week have evidence for shortening cold duration.

The most common zinc mistakes are taking it on an empty stomach and getting nausea, taking it at the same time as iron or a calcium-rich meal (which blocks both), and high-dose zinc for months without copper supplementation (which causes copper-deficiency anaemia and neurological symptoms). Another frequent error is choosing zinc oxide for its cheap price when zinc picolinate or bisglycinate absorbs far better per dose. Finally, zinc lozenges work for cold duration only when used as actual lozenges (sucked, not swallowed) within 24 hours of symptom onset; swallowed zinc capsules at the same dose do not produce the same effect.

When something has to be spaced apart, two slots are almost always enough. Put one group with your first meal and the other with your evening meal, roughly 8 to 12 hours apart, which comfortably clears the 2-hour intervals absorption conflicts require. Zinc goes in the evening slot, and anything it competes with goes in the other. Trying to run three or four slots is where routines break down, most people can hold two.

Absorption conflicts are dose-dependent, not absolute. Trace amounts in food, a splash of milk in coffee or the calcium in a slice of bread, are not the same as a 500mg supplement, and are not worth restructuring your day around. The interactions worth respecting are between two supplements at supplemental doses taken in the same swallow. If you are only taking Zinc and nothing else, spacing is a non-issue, keep it in a fixed slot and move on.

• Zinc and Iron
• Zinc and Calcium
• Zinc and Copper

• Iron
• Calcium
• Copper supplements (long-term)

• Do I need to take copper with zinc?+

  Yes if you are taking more than 25 to 40 mg of zinc per day for more than a few months. Long-term high zinc displaces copper at the intestinal transporter and causes copper-deficiency anaemia and neurological symptoms. A common ratio is 1 to 2 mg copper per 15 mg zinc. Short-term zinc for a cold (5 to 7 days) does not require copper.
• Can I take Zinc in the same handful as everything else?+

  Not quite. Zinc has documented conflicts with Iron and Calcium, which is what the spacing table above is for. Everything else can go in the same slot.
• Is spacing measured from swallowing or from digestion?+

  From swallowing. The intervals in the table are conventional practical margins that allow the first dose to clear the absorption window in the upper small intestine before the second arrives. There is no need to be precise to the minute, being roughly two hours apart is the point.

• Solomons NW. Am J Clin Nutr. 1986