Vitamin D vs Zinc

for immune function

Stronger evidence: tie

Stronger effect: Vitamin D

Safety: Vitamin D carries a minor interaction; Zinc has none recorded.

For immune function, the two are evidence-matched; the difference is in effect and safety.

grade C low certainty

modest reduction in acute respiratory infection risk, concentrated in deficient people

1000–2000 IU/day, adults

grade C low certainty

supplementation helps mainly when intake is deficient

sources: PMID:20000105 · PMID:00000024