Protocol · Immune System
Immune Health & Function Protocol
Vitamin D and Zinc are the core of this stack, with 2 supporting supplements. Each row gives the amount the protocol lists and the grade our evidence database holds for that supplement in Immune Health & Function.
We are re-verifying the studies cited on protocol pages; only confirmed citations are shown.
The stack
4 supplements · 2 graded · 2 confirmed studies
| Grade | Supplement | Amount listed | Why it’s in the stack | Evidence on file | Shop |
|---|---|---|---|---|---|
| Primary stackThe core of this protocol | |||||
| Vitamin D | Amount listed: 2,000–4,000 IU daily (target 40–60 ng/mL) | Activates antimicrobial peptide production (cathelicidin, defensins) and modulates T-cell and macrophage function
| Grade C for Body Fat165 people | ||
| Zinc | Amount listed: 15–30 mg daily | Essential cofactor for immune cell development, supports thymulin activity and T-lymphocyte proliferation
| Not graded yet | ||
Confirmed studies for Zinc (titles as PubMed lists them) | |||||
| Supporting stackListed as additions to the core | |||||
| Vitamin C | Amount listed: 500–1,000 mg daily | Enhances neutrophil function, supports epithelial barrier integrity, and provides antioxidant protection during immune response
| Grade C for Blood glucose3 studies · 28 people | ||
Confirmed studies for Vitamin C (titles as PubMed lists them) | |||||
| Elderberry | Amount listed: 300–600 mg daily (standardized extract) | Anthocyanins enhance cytokine production and have direct antiviral activity against influenza | Not graded yet | ||
Shop the evidence-backed picks
The collection holds the supplements we grade A or B for its theme, in third-party tested products where the catalog has them. It opens in our Fullscript store. You can look through it without signing in; Fullscript asks for a free account to order.
Or shop one supplement
Each opens third-party tested products, matched to the dose above where we can.
- Grade C
- Grade C
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How this protocol works
In plain language
Your immune system is a complex network of cells, tissues, and organs that defend against pathogens. Key players include white blood cells (neutrophils, lymphocytes, macrophages), antibodies, and various signaling molecules (cytokines). Nutritional deficiencies can impair immune function, making you more susceptible to infections.
- Vitamin D is crucial for immune function. It activates antimicrobial peptides—your body's natural antibiotics—and helps regulate the balance between fighting infection and preventing excessive inflammation. Deficiency is extremely common and associated with increased infection risk. A landmark meta-analysis showed vitamin D supplementation reduced respiratory infections by 12% overall, and by 42% in severely deficient individuals.
- Zinc is essential for immune cell development and function. It's required for the activity of over 300 enzymes, including those critical for immune response. Zinc deficiency impairs both innate and adaptive immunity. Supplementation has been shown to reduce infection rates, particularly in elderly populations.
- Vitamin C supports multiple aspects of immunity: it enhances neutrophil killing of pathogens, supports the skin and mucosal barriers, and protects immune cells from oxidative damage during the respiratory burst. While it may not prevent colds in everyone, it reduces severity and duration.
- Elderberry has direct antiviral properties and stimulates the immune system to produce more cytokines. Studies show it can reduce the duration and severity of colds and flu.
Expected timeline: Vitamin D takes 2-3 months to optimize levels. Zinc and vitamin C support occurs within days to weeks. Elderberry is most effective when started at the first sign of illness.