http://www.ana-jana.org/jana_journal.cfm (issue: JANA Volume 11, No. 1, 2008)Objective: Hypertension is a common condition with
high mortality from associated diseases. Epidemiological
evidence suggests that a dietary deficiency of vitamin C
may be a risk factor for hypertension. However, it remains
unclear whether vitamin C supplementation could reduce
Therefore, the purpose of this study was to
provide a comprehensive meta-analysis using randomized,
controlled trials looking at the effect of vitamin C supplementation
on blood pressure in patients with hypertension.
Methods: Nine randomized, controlled trials published
between 1966 and August 2007 with a total of 297 participants
were identified using MEDLINE and a manual
search. Using a random effects model, the effect sizes of
vitamin C supplementation on systolic and diastolic blood
pressure changes were estimated.
Results: Vitamin C supplementation was associated
with a significant reduction in systolic blood pressure with
an effect size of -2.37 mm Hg (95 % CI, -3.14 to -1.6 mm
Hg). However, the mean change in diastolic blood pressure
was non-significant with an effect size of only -0.37 mmHg
(95 % CI, -1.5 to 0.76 mm Hg).
Conclusion: Vitamin C supplementation in hypertensive
patients appears to possess modest effects on reducing
systolic blood pressure.