A cross-sectional study appearing in the American Journal of Epidemiology (Aug 15; 170 (4):464-71) correlated vitamin C levels and other disease markers in 979 nonsmokers. The subjects of the study were men and women were between the ages of 20 and 29 years who were participating in the Toronto Nutrigenomics and Health Study. Serum ascorbic acid (vitamin C) levels were measured in fasting, morning blood samples. Dietary intake was assessed for one month with a 196 item food frequency questionnaire.
It was determined that 14% of the subjects were deficient in vitamin C, and 33% had suboptimal levels of the nutrient. Low ascorbic acid levels were associated with high C-reactive protein levels. C-reactive protein (CRP) is a globular protein that increases in the serum as a response to injury or inflammation. It turns out to be a good predictor for cardiovascular disease. A study appearing in the Journal of the American Nutraceutical Association (2005;8(1):43-44), involving more than 27,000 women, found that CRP was a better predictor of cardiovascular disease than LDL (bad) cholesterol. High CRP levels are actually associated with increased mortality from all causes. A CRP level greater than 3 mg/L in men was found to increase the likelihood of death by nearly two-fold, according to research appearing in Clinical Chemistry (2008 Feb;54(2):335-42). The high CRP levels increased the likelihood of heart attack by a factor of 2.15 and increased the likelihood of cancer by a factor of 1.6.
The vitamin C deficient subjects also tended to have higher waist circumference, body mass index and blood pressure than did subjects with normal vitamin C levels. At least part of the problem was diet; one in seven of the subjects did not consume the recommended daily intake of vitamin C.
