Research synthesisModerate evidenceModerate effect4 studies · 4 beneficial · 0 neutral · 0 harmful
Across 4 studies, all reported beneficial effects of vitamin C on reducing systolic blood pressure, with a predominant moderate effect size. Two meta-analyses (the highest-quality evidence) found significant reductions, including an estimated 3.7 mmHg decrease in adults and benefits in individuals with type 2 diabetes. Studies ranged from 40 days in one trial to meta-analyses without specified durations, with a median study duration of 40 days, suggesting effects may appear within weeks.
- Studied populations: individuals with type 2 diabetes, adults, young healthy participants, heat-exposed workers
Caveats: Evidence base is small (only 4 studies) — conclusions should be considered preliminary. Available evidence is overwhelmingly positive — clinical literature in this area is subject to publication bias (null-result studies are less likely to be published or indexed). Doses varied widely or were not specified in most studies, so no clear effective dose range can be determined; one trial used 130 mg/day. Most studies lacked form data, so no form-specific conclusions can be drawn.
Generated Jun 11, 2026