Oral doses of Vitamin C greater than 500 milligrams per day may boost the health of the endothelium – the thin layer of cells lining the blood vessels – and boost overall heart health for people who need it the most, according to a meta-analysis of 44 clinical trials.
Scientists from Newcastle University in England report that endothelial function was significantly improved by vitamin C supplements in people with diabetes, atherosclerosis, and heart failure. No effects were observed in healthy volunteers, however, they reported in Atherosclerosis.
“To our knowledge, this is the first systematic review and meta-analysis evaluating the effect of supplemental vitamin C on endothelial function in human adults,” wrote the researchers, led by Ammar Ashor.
The Newcastle-based scientists pooled data from 44 clinical trials involving 1129 participants and found that, overall vitamin C supplements were associated with beneficial effects on endothelial function. Further crunching of the numbers indicated that the benefits appeared limited to people with atherosclerosis, diabetes, and heart failure.
Commenting on the potential mechanism of action, the researchers noted that both oxidative damage and vascular inflammation are known to affect endothelial function, while nitric oxide (NO) – a potent vasodilator- is a major player in preserving endothelial function.
“These results support the idea that vitamin C may be a useful nutritional intervention for the secondary prevention of cardiovascular diseases, ” they concluded.
Source: Atherosclerosis, Volume 235, Issue 1, pages 9-20. “Effects of vitamin C on endothelial function in health and disease: A systematic review and meta-analysis of randomized controlled trials “. Authors: A. W> Ashor,J. Lara, J. C. Mathers, M. Siervo.