People with hypertension have a relatively low serum vitamin C. - GreenMedInfo Summary

Background: Hypertension is regarded as a major and independent risk factor of cardiovascular diseases, and numerous studies observed an inverse correlation between vitamin C intake and blood pressure.

Aim: Our aim is to investigate the relationship between serum vitamin C and blood pressure, including the concentration differences and the correlation strength.

Method: Two independent researchers searched and screened articles from the National Library of Medicine, Cochrane Library, Web of Science, China National Knowledge Infrastructure, VIP databases, and WANFANG databases. A total of 18 eligible studies were analyzed in the Reviewer Manager 5.3 software, including 14 English articles and 4 Chinese articles.

Results: In the evaluation of serum vitamin C levels, the concentration in hypertensive subjects is 15.13 mol/L lower than the normotensive ones (mean difference = -15.13, 95% CI [-24.19, -6.06], and= 0.001). Serum vitamin C has a significant inverse relation with both systolic blood pressure (Fisher's = -0.17, 95% CI [-0.20, -0.15],<0.00001) and diastolic blood pressure (Fisher's = -0.15, 95% CI [-0.20, -0.10],<0.00001).

Conclusions: People with hypertension have a relatively low serum vitamin C, and vitamin C is inversely associated with both systolic blood pressure and diastolic blood pressure.