vitamin
Vitamin C
Essential antioxidant vitamin for immunity, collagen production and iron absorption.
Overview
Vitamin C (ascorbic acid) is a water-soluble essential vitamin — the body cannot produce it and relies entirely on dietary intake. It plays a critical role in collagen synthesis, immune function, antioxidant defence and iron absorption from plant foods. It is widely taken at high doses during illness, though the evidence for cold prevention is more nuanced than popular belief suggests. The body saturates at around 200mg per day; above that, absorption efficiency drops and excess is excreted.
Evidence rating
Strong evidence for vitamin C's role in collagen synthesis, immune function and antioxidant protection. Moderate evidence for cold duration reduction when supplementing regularly. Evidence for cold prevention is limited to people under extreme physical stress. At high doses, benefits plateau quickly due to saturation kinetics.
Common uses
- Strong EvidenceCollagen synthesis and skin health
- Strong EvidenceImmune system support
- Strong EvidenceAntioxidant protection
- Strong EvidenceEnhancing iron absorption from plant foods
- Moderate EvidenceReducing cold duration when supplementing regularly
Safety & cautions
Worth checking with a pharmacist if you take medication.
Common forms
The basic form. Cheap, effective and well-studied.
Non-acidic form. Gentler on the stomach at higher doses.
Encapsulated for enhanced absorption. Useful for those who cannot tolerate high-dose standard vitamin C.
Food sources
- Red bell pepperApprox. 190mg per 100g — one of the richest sources
- Kiwi fruitApprox. 93mg per fruit
- StrawberriesApprox. 59mg per 100g
- Broccoli (raw)Approx. 89mg per 100g
- BlackcurrantsApprox. 200mg per 100g — exceptionally rich