A new meta-analysis has revealed that taking vitamin C supplements on a short term basis may lower blood pressure, and have greater results for those with high blood pressure.

The supplementation of vitamin C was associated with significant reductions in systolic and diastolic blood pressure of 3.84 and 1.48mm Hg. Data was analysed using individuals with high blood pressure (hypertension) and showed that vitamin C supplements were associated with systolic and diastolic blood pressure reductions of 4.85 and 1.67mm Hg, researchers reported from Johns Hopkins Medical Institution.

"Before vitamin C supplementation can be recommended for the prevention of hypertension or as adjuvant antihypertensive therapy, additional trials are needed, designed with large sample sizes, and with attention to quality of blood pressure assessment."

One death every 39 seconds

There are about one billion people worldwide suffering from high blood pressure. High blood pressure is defined by having a systolic and diastolic blood pressure (BP) greater than 140 and 90mmHg.

Cardiovascular disease accounts for a death in the US every 39 seconds, according to the most recent data from the American Heart Association, and around 33.5% of US adults suffer from hypertension.

Vitamin C

The John Hopkins researchers collected data from 29 clinical trials, with the median dose of vitamin C calculated to be 500 milligrams per daym and a median trial duration of eight weeks. Vitamin C supplementation was associated with a significant reduction observed in people with hypertension. 

"Although our meta-analysis reported significant BP-lowering effects with vitamin C supplementation, several long-term trials powered for clinical endpoints have not shown benefit," wrote the researchers."Long-term trials with clinical endpoints are difficult and costly but are still needed to determine whether vitamin C supplementation reduces the risk of cardiovascular events."

Source: American Journal of Clinical Nutrition 

Study: "Effects of vitamin C supplementation reduces the risk of cardiovascular events."