Zinc

Supplements · Minerals · Supplement, Typed Supps

Your body needs it for hundreds of jobs, especially your immune system.

Stage by stage

Intake (Tablet): Stomach acid frees zinc from the tablet.
Small intestine (Dedicated transporters): Absorbed via transporters that compete with iron and calcium.
Bloodstream (Carried by transport proteins): Absorbed zinc binds to transport proteins in the blood, carried to tissues that need it.
Immune cells (Enzyme cofactor): Required for immune cell function and wound healing.

Shortening a cold when started within 24 hours of symptoms — moderate evidence. Lozenges at high doses shorten colds by roughly a day in pooled analyses. Timing is critical, and the taste and nausea cause many people to stop.
Correcting a documented deficiency — strong evidence. Clear, and important — deficiency impairs immune function, wound healing, and taste.
Reducing progression of age-related macular degeneration, in a specific combination — moderate evidence. The AREDS formulation, which includes zinc, slowed progression in people who already had intermediate disease. It did not prevent it in healthy eyes.
Raising testosterone in men who are not deficient — insufficient evidence. Correcting a deficiency can normalise levels. Adding zinc on top of adequate status does not raise them further.

8–15 mg daily; short courses for colds use more

Upper limit: 40 mg daily for adults

Best empty-stomach, but often taken with food to avoid nausea.

Quinolone and tetracycline antibiotics: Zinc binds them and reduces absorption. Separate by several hours. (high)
Penicillamine: Zinc substantially reduces its effect. (high)
Thiazide diuretics: Increase zinc loss in urine over time. (moderate)

“Zinc lozenges cure a cold.” In reality: May modestly shorten duration if started within 24 hours — doesn’t prevent colds.