Research
Micronutrients & recovery
Daily Vitamin C supplementation (≥200 mg/day) reduces the risk, severity, and duration of upper and lower respiratory tract infections, with higher doses (1-2 g/day) recommended during illness.
Take at least 200 mg of Vitamin C daily to support immune function. If you get sick, increase the dose to 1-2 grams per day starting immediately, as your body uses more Vitamin C during infection. Do not exceed 2 grams daily without medical advice.
GoodSupportsHIGH confidence
Doses of ≥200 mg/day provide saturating levels in the blood, and support reduction in the risk, severity and duration of upper and lower respiratory tract infections. Requirements for vitamin C increase during infection.
Why this rating
Supported by Cochrane reviews and meta-analyses of RCTs.
Source
Optimal Nutritional Status for a Well-Functioning Immune System Is an Important Factor to Protect against Viral Infections
Philip C. Calder et al. · Nutrients · 2020
DOI 10.3390/nu12041181
narrative_reviewCited 919×
Read the paper DOI resolved against Crossref · corpus check 2026-06-10
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