Background: In observational studies, increased vitamin C intake, vitamin C supplementation, and higher blood concentrations of vitamin C are associated with lower blood pressure (BP). However, evidence for blood pressure-lowering effects of vitamin C in clinical trials is inconsistent. Objective: The objective was to conduct a systematic review and meta-analysis of clinical trials that examined the effects of vitamin C supplementation on BP. Design: We searched Medline, EMBASE, and Central databases from 1966 to 2011. Prespecified inclusion criteria were as follows: 1) use of a randomized controlled trial design; 2) trial reported effects on systolic BP (SBP) or diastolic BP (DBP) or both; 3) trial used oral vitamin C and concurrent control groups; and 4) trial had a minimum duration of 2 wk. BP effects were pooled by random-effects models, with trials weighted by inverse variance. Results: Twenty-nine trials met eligibility criteria for the primary analysis. The median dose was 500 mg\/d, the median duration was 8 wk, and trial sizes ranged from 10 to 120 participants. The pooled changes in SBP and DBP were -3.84 mm Hg (95% CI: -5.29, -2.38 mm Hg; P < 0.01) and -1.48 mm Hg (95% CI: -2.86, -0.10 mm Hg; P = 0.04), respectively. In trials in hypertensive participants, corresponding reductions in SBP and DBP were -4.85 mm Hg (P < 0.01) and -1.67 mm Hg (P = 0.17). After the inclusion of 9 trials with imputed BP effects, BP effects were attenuated but remained significant. Conclusions: In short-term trials, vitamin C supplementation reduced SBP and DBP. Long-term trials on the effects of vitamin C supplementation on BP and clinical events are needed.\n\n\n
Stephen P Juraschek, Eliseo Guallar, Lawrence J Appel, Edgar R Miller 3rd<\/p>\n
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Summary Background: In observational studies, increased vitamin C intake, vitamin C supplementation, and higher blood concentrations of vitamin C are associated with lower blood pressure (BP). However, evidence for blood pressure-lowering effects of vitamin C in clinical trials is inconsistent. Objective: The objective was to conduct a systematic review and meta-analysis of clinical trials that…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[69],"tags":[545],"_links":{"self":[{"href":"https:\/\/www.healthlibrary.info\/wp-json\/wp\/v2\/posts\/7220"}],"collection":[{"href":"https:\/\/www.healthlibrary.info\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.healthlibrary.info\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.healthlibrary.info\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.healthlibrary.info\/wp-json\/wp\/v2\/comments?post=7220"}],"version-history":[{"count":0,"href":"https:\/\/www.healthlibrary.info\/wp-json\/wp\/v2\/posts\/7220\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.healthlibrary.info\/wp-json\/wp\/v2\/media?parent=7220"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.healthlibrary.info\/wp-json\/wp\/v2\/categories?post=7220"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.healthlibrary.info\/wp-json\/wp\/v2\/tags?post=7220"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}