Supplements for immunity
What helps a cold, what helps prevention, and what the supplement aisle gets wrong.
Zinc 13–23 mg lozenges started within 24 h of cold symptoms shorten illness by ~33% (Hemilä Cochrane). Vitamin C 1 g daily reduces cold severity and duration by ~8% (Cochrane 2013) — meaningful for athletes/cold environments, modest for general public. Vitamin D3 if deficient reduces respiratory infection rates. Elderberry has positive but limited data for cold/flu. Avoid: high-dose immune-stimulating herbs (echinacea, andrographis, mushroom polysaccharides) if you are immunosuppressed — they may counteract therapy.
Evidence summary
The numbers on the cards are the same composite as the supplement pages: efficacy, safety, research, onset, cost, and drug-interaction ratings, from 20 to 100. The strongest records on this page are Electrolyte complex (Na/K/Mg), Saccharomyces boulardii, and Vitamin D3. A higher score is a stronger record in the database, not a personal recommendation.
Who should be careful
- Pregnancy, breastfeeding, children, and anyone taking a prescription drug should talk with a clinician before using this list.
- Do not stack products from this list that sedate, thin the blood, or lower blood sugar with medicines that do the same thing.
Comparisons and topic guides
90
Electrolyte complex (Na/K/Mg)
80
Saccharomyces boulardii
83
Vitamin D3
81
Zinc
80
Lactobacillus rhamnosus GG
77
Vitamin D3 liquid drops
75
Zinc picolinate
70
Acerola cherry extract
76
Vitamin C (moderate dose)
76
Tyrosine (L-tyrosine)
67
Nicotinic acid (Niacin, flush form)
76
Lactobacillus plantarum 299v
75
Lactobacillus acidophilus
74
DGL Licorice (deglycyrrhizinated)
74
Niacinamide (nicotinamide)
73
Vitamin A (retinol, low-dose)
73
Cranberry extract
73
Vitamin K1 (phylloquinone)
73
Zinc gluconate
72
Saffron (Crocus sativus)
72
Lactobacillus plantarum
72
Beta-glucan (1,3/1,6)
72
Zinc carnosine
72
Bifidobacterium lactis (BB-12 / HN019)
72
Lactobacillus casei Shirota
Educational reference, not medical advice. Discuss any supplement change with a qualified clinician before acting on this list.