EFSA zinc needs rise with phytate in the diet (whole grains, legumes): men 9.4 to 16.3 mg, women 7.5 to 12.7 mg. PillMath shows the middle value (600 mg phytate a day). Pregnancy adds 1.6 mg, breastfeeding 2.9 mg.
These are doses tested in research, not personal advice. Some exceed the upper limit because they were short courses or given under medical care.
Moderate evidenceModerate: smaller trials, mixed results or official guidance.Based on 1 meta-analysis. 1 finding disagrees.How grades work
Shorter colds (short course of lozenges)
80-92 mg a day, for a few days only
Three trials (199 patients) used 80 to 92 mg zinc a day as zinc acetate lozenges, started within 24 hours of symptoms. By day 5, 70% had recovered versus 27% on placebo. This is a few days only: it is well above the safe limit for daily use.
A 2024 Cochrane review of zinc for colds found the evidence uncertain: zinc may shorten colds slightly, but trials were mixed and prevention was not shown.
AREDS gave 80 mg zinc (with 2 mg copper to prevent copper deficiency) to people with intermediate macular degeneration, alone or with antioxidants. The full combination lowered the odds of advanced disease. This is long-term use far above the safe limit, under an eye doctor's care.
Citrate, salt weight (~31% Zn) (a good choice among equals)
Why: Zinc citrate and gluconate are absorbed about equally well, around 61% in young adults, and zinc oxide around 50%. Labels give the elemental zinc, which is what to compare.
Alternatives: Picolinate is often sold as the best absorbed form. One small double-blind crossover in 15 adults found it raised hair, urine and red-cell zinc where citrate and gluconate did not, but that was 1987, those markers are weak and no one has repeated it.
CopperModerate evidenceModerate: smaller trials, mixed results or official guidance.Based on 1 randomised trial, 1 official reference.How grades work
Zinc at 50 mg a day or more for weeks can block copper absorption and lead to copper deficiency. The AREDS eye formula added 2 mg copper to its 80 mg zinc for this reason.