Dosage · Supplement
Vitamin C: dosage and how to take it
75–120 mg/day from food or supplement.
- Overall grade
- Grade A
- Last revised
- 0
- graded outcomes
- 1
- reference listed
Assembled by the app from other entries in this library. It adds no evidence of its own — follow the links to the entries it draws on.
The evidence in words
How much to take
75–120 mg/day covers requirements; 200–500 mg is a common well-absorbed supplemental dose. Split doses above ~500 mg — absorption fraction falls as the dose rises. Take with a plant-iron source when the goal is iron absorption.
Timing & separation
There are no strict timing conflicts on record for Vitamin C; consistency matters more than the exact hour for most goals.
Why the dose is what it is
Ascorbate donates electrons, regenerating other antioxidants and serving as a cofactor for prolyl and lysyl hydroxylases that stabilize collagen's triple helix — which is why deficiency causes the connective-tissue breakdown of scurvy. In the gut it reduces ferric to ferrous iron, sharply improving non-heme (plant) iron absorption.
Bottom line
Eat the fruit and vegetables; a 200–500 mg supplement is a reasonable, cheap margin. Best evidence-backed uses are preventing deficiency, supporting collagen, shortening colds slightly, and boosting plant-iron uptake — not curing disease.
How it is used
As the entry records it, from the studies it summarises. Not a recommendation for you — doses that suit a trial population may not suit you.
- Requirement
- 75–120 mg/day from food or supplement.
- Supplemental
- 200–500 mg/day; split larger doses.
Goes with
- Vitamin CFull Vitamin C monographEvidence grade A
Related reading
Entries that share this one's tags or conditions.
- Chaga: dosage and how to take itAvoid high doses (oxalates).Evidence grade D
- Vitamin C for Cancer / CVD preventionEvidence grade D — Oral megadose trials nullEvidence grade D
- Vitamin C for Cold durationEvidence grade B — Cochrane: modest shortening, not preventionEvidence grade B
- Vitamin C for Non-heme iron absorptionEvidence grade A — ~2–3× when taken togetherEvidence grade A
Sources
As this entry records them: title, journal and year. None carries a DOI or PubMed id, so none is linked as a verified paper. Each link searches PubMed for the title; check that what you find is what the entry describes.
- 1.Vitamin C for preventing and treating the common cold (Cochrane review) — Cochrane Database Syst Rev, 2013. Search PubMed (opens in a new tab)
Last revised . A grade is this entry's reading of the evidence, not medical advice.