NutriStack
Oseltamivir and Vitamin D3, a synergy.
Vitamin D supplementation modestly reduces the risk of acute respiratory infections, particularly in deficient individuals, per a large individual participant data meta-analysis. While direct combination trials with oseltamivir are absent, maintaining adequate vitamin D status supports antiviral immune function and is a reasonable background measure during influenza treatment.
One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
Same shape as the other 1,729 pairs in the public database.
From the interaction database
What the row says.
Every entry follows the same shape: what is happening, the mechanism, the recommendation, and the primary literature.
At a glance
- Substances
- Oseltamivir and Vitamin D3
- Pair type
- Synergy
- Evidence (highest tier)
- Moderate
- Source citations
- 2 sources
- Stack Score effect
- +2 to your Stack Score (per scored synergy row).
- Scope
- Supplement × Prescription
- Last verified
- May 30, 2026
Synergy · Moderate evidence
Synergy
What is happening. Vitamin D supplementation modestly reduces the risk of acute respiratory infections, particularly in deficient individuals, per a large individual participant data meta-analysis. While direct combination trials with oseltamivir are absent, maintaining adequate vitamin D status supports antiviral immune function and is a reasonable background measure during influenza treatment.
Mechanism. Vitamin D upregulates antimicrobial peptides (cathelicidin, defensins) and modulates innate and adaptive antiviral immunity. Oseltamivir directly inhibits influenza neuraminidase.
Recommendation. If your vitamin D level is low or unknown, maintaining 1000-2000 IU/day vitamin D3 is reasonable alongside oseltamivir during influenza season. Do not use vitamin D as treatment for active influenza in lieu of oseltamivir.
Sources (2)
- Martineau AR, et al. Vitamin D supplementation to prevent acute respiratory infections: individual participant data meta-analysis. Health Technol Assess. 2019;23(2):1-44. PMID 30675873
- Zhu Z, et al. Association between vitamin D and influenza: meta-analysis and systematic review of randomized controlled trials. Front Nutr. 2022;8. PMID 35071300
Stack Score
How this pair moves the number.
Effect on the composite score
If both Oseltamivir and Vitamin D3 are in the same stack, this pair applies +2 to your Stack Score (per scored synergy row).
The full algorithm, the clamping rules, and four worked stacks are documented at /methodology/stack-score.
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