Best Supplements for Immune Support
7 evidence-based supplement recommendations to support your immune support goals.
A healthy immune system depends on adequate nutrition, sleep, exercise, and stress management. While no supplement can prevent illness, certain nutrients play critical roles in immune cell function, and deficiency in these nutrients impairs immune response. Here are the supplements with the strongest evidence for immune support.
Top Recommended Supplements
Vitamin D3
Vitamin D receptors are present on virtually all immune cells. It modulates both innate and adaptive immunity and helps regulate the inflammatory response.
Meta-analysis of 25 RCTs (11,321 participants) showed 12% reduction in respiratory infections. Strongest effect in those with baseline deficiency.
Morning with a fat-containing meal
Zinc
Essential for the development and function of immune cells (neutrophils, NK cells, T-cells). Zinc deficiency impairs immune function within days.
Meta-analysis shows zinc lozenges reduce cold duration by 33% when started within 24 hours of symptoms.
With food. Lozenges for acute cold symptoms.
Vitamin C
Supports epithelial barrier function, enhances pathogen killing by neutrophils, and supports lymphocyte function. Concentrated in immune cells at levels 10-100x higher than plasma.
Regular supplementation reduces cold duration by 8% in adults. More significant effect in those under physical stress (14% reduction).
Split into 2 doses for better absorption
Elderberry
Rich in anthocyanins with antiviral properties. Inhibits viral replication and enhances cytokine production for immune response.
Meta-analysis shows significant reduction in upper respiratory symptoms duration and severity.
Daily for prevention, or at first sign of illness
Probiotics
70% of the immune system resides in the gut. Probiotics support gut barrier integrity and modulate immune cell activity through the gut-associated lymphoid tissue (GALT).
Meta-analysis shows 47% reduction in respiratory infection incidence and shorter duration of illness.
Morning on an empty stomach
Recommended Protocol
Ensure vitamin D levels are optimal (40-60 ng/mL) — this is the single most impactful step. Add zinc and vitamin C as daily support. Probiotics for gut-immune axis. Elderberry during cold/flu season or at first sign of illness.
Suggested Stack
Daily Prevention: Vitamin D3 (3,000 IU) + Zinc (15mg) + Vitamin C (500mg) + Probiotics (15B CFU). Acute Illness: Add Elderberry (1,000mg) + increase Zinc to 30mg + increase Vitamin C to 1,000mg.
Build this stack in our Stack BuilderExpected Timeline
Vitamin D: 2-3 months to optimize blood levels. Zinc/Vitamin C: ongoing support. Elderberry: acute use within 24-48 hours of symptoms. Probiotics: 2-4 weeks to establish gut colonization.
Important Warnings
- Do not mega-dose vitamin C (>2g/day) — excess is excreted and may cause GI upset
- Zinc lozenges can cause nausea if taken on empty stomach
- Long-term zinc >40mg/day requires copper supplementation
- Elderberry should not replace medical treatment for serious infections
Frequently Asked Questions
Can supplements prevent COVID-19 or the flu?
No supplement can prevent viral infections. However, optimizing vitamin D, zinc, and vitamin C levels supports your immune system's ability to respond effectively. Vaccination remains the most effective prevention strategy for specific diseases.
Should I take immune supplements year-round?
Vitamin D and probiotics are beneficial year-round. Zinc and vitamin C can be taken daily at maintenance doses. Elderberry is best used seasonally (fall/winter) or at the first sign of illness.
Explore Other Goal Guides
Medical Disclaimer: This guide is for educational purposes only. Supplement recommendations are based on published research but individual needs vary. Always consult with a qualified healthcare provider before starting any supplement regimen, especially if you have pre-existing conditions or take medications.