Best Supplements for Immune Health
The aging immune system drifts toward chronic inflammation and weaker responses. These compounds correct common deficiencies and modulate immune tone — with the important caveat that supplementing beyond sufficiency rarely adds benefit and can add risk.
Ranked by strength of human evidence (Tier A > B > C) and mechanistic fit — computed from the compound registry, not hand-picked. Every entry links to its full evidence deep-dive with PubMed citations. Educational only, not medical advice.
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Vitamin D3 (Cholecalciferol)
Tier BVDR Nuclear Receptor Activation — Tier B.
1000–2000IU/day (25–50µg), with the largest fat-containing meal·AM·3 PMIDs - 2
Zinc
Tier BImmune & Antioxidant Cofactor Biology — Tier B.
15–30mg/day elemental, with a light meal (below the 40mg/day UL)·AM/PM·3 PMIDs - 3
Omega-3 (EPA + DHA)
Tier ASpecialized Pro-resolving Mediators (SPMs) — Tier A.
2–4g combined EPA+DHA daily (with fat-containing meals)·AM/PM·3 PMIDs - 4
Selenium
Tier BSelenoenzyme Redox Cofactor — Tier B.
55µg/day (RDA); 55–100µg/day only to correct a documented deficiency — do not exceed long-term·AM·3 PMIDs - 5
GlyNAC
Tier AGlutathione Synthesis — Tier A.
600mg glycine + 600mg NAC·AM·2 PMIDs - 6
Sulforaphane
Tier ANRF2 Activation — Tier A.
10–35mg glucoraphanin·AM·2 PMIDs - 7
Taurine
Tier BOsmolyte / Mitochondrial Buffer — Tier B.
1–3g taurine daily·AM/PM·1 PMID - 8
NMN
Tier ANAD+ Restoration — Tier A.
250–500mg NMN·AM·3 PMIDs
The aging mechanisms behind this goal
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What is the best supplement for immune support?
Correcting a zinc or vitamin D deficiency has the clearest immune benefit — both have human RCT data in deficient or older populations. Supplementing when you are already replete adds little and, for zinc above 40mg/day, can deplete copper.