Effect of Vitamin C Supplementation on Blood Pressure Level in Type 2 Diabetes Mellitus: A Randomized, Double-Blind, Placebo-Controlled Trial

Abstract

Hypertension is one of the common problems in diabetic people. There are evidences suggesting that oxidative stress plays an important role in the development of hypertension. It is possible that decreased antioxidant activity levels of reactive oxygen species scavengers such as vitamin C contribute to decreasing oxidative stress. This study was aimed to investigate the effect of vitamin C on blood pressure in people with type 2 diabetes. The present randomized controlled trial study was conducted on 84 patients with type 2 diabetes undergoing hypertension in the Diabetes Research Center of Tehran University of Medical Sciences, Iran, in 2014. Samples were randomly divided into two groups of vitamin C (n = 42) and placebo (n = 42) on the basis of the random permuted block method. The intervention group was given chewable vitamin C supplements at a dose of 250 mg 4 times a day and the control group was given its placebo for 45 days. The blood pressure of two groups was measured at baseline and in the end of the study. Data were analyzed using SPSS 16 software. No significant differences were observed in the average weight and body mass index, waist and hip circumference and daily intake of energy and its component between the two groups at the beginning and the end of the study. The mean of systolic (129.6±24.4 in vitamin C group and 129±14.1 in placebo, P=0.89) and diastolic (77.2±12.6 in vitamin C group and 76.5±9.65 in placebo, P=0.77) blood pressure at baseline was not significant between the two groups, but at the end of the study, findings showed that there is a significant difference between systolic (121.6±24.4 in vitamin C group and 129.2±13.5 in placebo, P<0.0001) and diastolic (72.5±11 in vitamin C group and 77.4±9.2 in placebo, P<0.0001) blood pressure of two groups.Conclusion: According to the result of this study, the consumption of vitamin C supplement may cause a reduction in blood pressure in patients with type 2 diabetes mellitus. Therefore, in order to improve the health of these people, increasing intake of vitamin C is recommended.

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Effects of Vitamin C Supplementation on Glycemic Control and Cardiovascular Risk Factors in People With Type 2 Diabetes: A GRADE-Assessed Systematic Review and Meta-analysis of Randomized Controlled Trials

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