Benefits of Vitamin C

Evidence-Based Benefits

• Immune defense — a 2013 Cochrane review of 29 RCTs (n=11,306) found regular vitamin C supplementation reduced cold duration by 8% in adults and 14% in children, with greater benefit in those under physical stress
• Antioxidant protection — vitamin C is the primary water-soluble antioxidant in plasma, scavenging reactive oxygen species and regenerating vitamin E, reducing oxidative damage linked to chronic disease
• Collagen synthesis — vitamin C is an essential cofactor for prolyl and lysyl hydroxylase, enzymes required for collagen cross-linking; deficiency causes scurvy with impaired wound healing within weeks
• Iron absorption enhancement — co-ingestion of 100 mg vitamin C with a meal increases non-heme iron absorption by up to 67%, making it critical for those at risk of iron deficiency

What the Research Says

Vitamin C has a robust evidence base spanning decades of research. The landmark 2013 Cochrane review by Hemilä and Chalker analyzed 29 trials (n=11,306) and found that regular vitamin C supplementation (≥200 mg/day) reduced cold duration by 8% in adults but did not reduce cold incidence in the general population. However, five trials in participants under heavy physical stress (marathon runners, soldiers, skiers) showed a 52% reduction in cold incidence. Carr and Maggini (2017) reviewed vitamin C's role in immune function, demonstrating it supports both innate and adaptive immunity through multiple mechanisms including neutrophil function, lymphocyte proliferation, and antibody production.

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