Vitamin C and Blood Pressure: Evidence, Usage, and Safety
Reading time: 8–10 minutes • Educational only.
What the research suggests (human data)
- Meta-analysis (2012, 29 RCTs): median dose ~500 mg/day for 8 weeks; pooled effect SBP −3.84 mmHg and DBP −1.48 mmHg vs placebo.
- Recent reviews (2023–2024): overall, vitamin C shows modest, short-term BP effects with study heterogeneity.
Takeaway: Vitamin C’s BP effect is small on average and should be viewed as an adjunct to core habits and prescribed care.
How to use (study-aligned, food-first)
- Food first: rely on fruits and vegetables when possible.
- If trialing a supplement with your clinician: consider ~500–1,000 mg/day for 8–12 weeks; do not exceed the UL 2,000 mg/day without guidance.
- Track a 7-day average before and after 2–4 weeks: How to Measure & Track.
Safety & cautions
- Kidney stones (men): high-dose supplemental vitamin C has been associated with a higher risk in men. Prefer food-first or moderate dosing; discuss with your clinician if you have a stone history.
- GI effects at high doses: diarrhea and stomach upset become more likely above 2,000 mg/day.
- Special cases: iron-overload disorders, advanced kidney disease, or G6PD deficiency—seek individualized advice.
Pair with fundamentals
Educational Disclaimer: This article is for educational purposes only and is not medical advice.
References
- Juraschek SP, et al. Effects of vitamin C on BP — meta-analysis. Am J Clin Nutr.
- NIH ODS — Vitamin C Health Professional Fact Sheet (UL 2,000 mg/day). ODS.
- Ferraro PM, et al. Vitamin C intake & kidney stones (sex-specific findings). PubMed ; PMC.
- Recent reviews/meta-analyses on vitamin C & BP. PubMed.
