Extra Vitamin C May Aid in Blood Pressure Control
According to a new study, vitamin C supplements may help lower blood pressure. Scientists analyzed data from 29 different clinical trials and approximately 1,400 adults aged 22 to 74 in this review study.
The study participants consumed 500 milligrams of supplemental vitamin C per day for an average of eight weeks. Systolic blood pressure (the top number in a reading) dropped by nearly 5 points in people with high blood pressure, while diastolic blood pressure (the bottom number) dropped by about 1.7 points.
"Our research suggests that vitamin C supplementation has a modest blood pressure-lowering effect," says researcher Edgar "Pete" R. Miller III, MD, Ph.D. in a news release.
"However, before we can recommend supplements as a treatment for high blood pressure, we need more research to understand the implications of taking them," says Miller, an associate professor of general internal medicine at the Johns Hopkins School of Medicine in Baltimore.
Other research has suggested a link between higher vitamin C intake from food or supplements and lower blood pressure. However, clinical trial evidence of this effect has been mixed.
High blood pressure affects nearly one-third of all American adults, increasing their risk of heart disease and stroke. Dietary changes, exercise, quitting smoking, losing weight, and medication is commonly used to treat the condition.
Modest Blood Pressure Changes:
Taking vitamin C supplements at a dose of about 500 milligrams per day appeared to reduce systolic blood pressure by nearly 4 points and diastolic blood pressure by about 1.5 points in about two months across all studies — some with healthy adults and others with people with high blood pressure.
The best dietary sources of this antioxidant-rich vitamin are fruits and vegetables, particularly red pepper, oranges, grapefruit, and kiwi.
Adult women should consume 75 milligrams of vitamin C per day, while adult men should consume 90 milligrams per day. The Institute of Medicine recommends a daily maximum of 2,000 milligrams of vitamin C for both adult males and adult females.
However, the scientists claim that many of the studies were small and that vitamin C was taken in addition to blood pressure medication in some of them. They are not yet suggesting that the supplement is a natural alternative to blood pressure medications.
It's unclear whether taking vitamin C for more than two months will result in long-term blood pressure changes.
"Although our review found only a moderate impact on blood pressure, lowering blood pressure by 3 [points] would result in a lot fewer strokes," the researchers write.