Higher vitamin C levels associated with lower blood pressure in young women

In an article published online on December 17, 2008 in Nutrition Journal, Gladys Block of the University of California, Berkeley and her associates report that young women who have higher plasma levels of vitamin C have lower systolic and diastolic blood pressure as well as a reduced increase in blood pressure over a one year period compared with those whose levels of the vitamin are low.
The current analysis included 242 African-American and Caucasian participants in the National Heart, Lung and Blood Institute Growth and Health Study, a ten year longitudinal study designed to evaluate the development of obesity in adolescent girls aged 8 to 11 upon enrollment. Blood pressure was measured at the ninth and tenth annual follow-up visit, and blood samples obtained at the tenth visit were analyzed for plasma ascorbic acid (vitamin C) levels.

Following adjustment for body mass index and other factors, the research team found that women whose plasma vitamin C levels were among the top 25 percent had systolic blood pressure that averaged 4.66 mmHg lower and diastolic blood pressure that averaged 6.04 mmHg lower than women whose vitamin C was in the lowest 25 percent. When blood pressure readings from the tenth year of the study were compared with those of the ninth year, women with plasma vitamin C in the lowest 25 percent were found to have experienced an average diastolic increase of 5.97 mmHg, while those whose vitamin C levels were highest had only a 0.23 mmHg increase. A similar effect was observed for systolic blood pressure. Continue Reading

Vitamin D deficiency: emerging cardiovascular disease risk factor

A review published in the December 9, 2008 issue of the Journal of the American College of Cardiology describes the involvement of deficient vitamin D levels in common risk factors for cardiovascular disease (including high blood pressure, diabetes, and obesity) and in cardiovascular events.Vitamin D deficiency is estimated to affect up to half of all adults and 30 percent of children in the United States.

While the vitamin’s role in bone health has long been known, a flurry of recent studies have uncovered associations between deficient levels of the vitamin and a number of diseases, including cardiovascular disease. In their review, Michael F. Holick, MD, PhD and colleagues note that insufficient levels of vitamin D activate the renin-angiotensin-aldosterone system, which can lead to hypertension and thickening of the heart and blood vessel walls.

Altered hormone levels related to a deficiency of vitamin D (which is also a hormone) increase the risk of diabetes, which is a well known risk factor for the development of cardiovascular disease. In 15,088 subjects from the NHANES III national cohort registry, higher vitamin D levels were related to a lower risk of diabetes as well as hypertension, high triglycerides, and obesity. And among Framingham Heart Study participants who had levels of vitamin D of less than 15 nanograms per milliliter upon enrollment, the risk of subsequent cardiovascular events was twice as great as the risk experienced by those with higher levels of the vitamin. Continue Reading