Vitamin C Supplementation May Reduces Risk of Heart Attack and Stroke

James Meschino DC, MS, ROHP

Reporting in the February, 1988 edition of the American Journal of Clinical Nutrition, D. Harats and fellow researchers compared cardiovascular risk factors in subjects consuming 50 mg of vitamin C with those who were later assigned a vitamin C supplement of 500 mg per day for a two-month period.

In the subjects receiving the vitamin C supplement, blood levels of vitamin C rose from 13.5 micromoles per liter to 51.7 micromoles per liter.

Previously F. Gey demonstrated in the large MONICA study (a study involving 10 countries) that vitamin C blood levels above 50 micromoles per litre was associated with more than a 50% reduction in heart disease mortality rates. This reduction was experienced in contrast to populations where blood vitamin C levels averaged between 15-27 micromoles per litre.

In the MONICA study, low blood levels of vitamin C and vitamin E (vitamin E below the range of 25-30 micromoles per litre) were stronger predictors of future heart disease mortality than blood cholesterol levels, smoking or high blood pressure, which are known cardinal risk factors.

In a 20-year follow-up study, analysis of mortality in patients in the United Kingdom who were older than 65 years of age showed that low vitamin C status (either dietary intake or blood levels) was strongly associated with increased subsequent risk of death from stroke. A Swiss study uncovered an identical finding and was reported in 1993 in The Journal of Clinical Investigation by F.Gey, H. Stahelin and associates.

In the most recent study by D. Harats, the group receiving 500 mg of vitamin C not only attained more optimal blood levels of vitamin C, but also demonstrated other favorable indicators related to a decreased risk for cardiovascular disease.

The subjects ingesting 500 mg per day of vitamin C also showed decreased free radical damage to cholesterol in laboratory studies. When blood cholesterol becomes damaged by free radicals, it has a greater tendency to stick to the walls of the artery causing narrowing and blockage.

A number of prior studies have demonstrated that vitamin E protects blood cholesterol from free radical attack. It appears that vitamin C may share this important role as a water-soluble antioxidant circulating in the bloodstream. In fact, higher doses of vitamin C (500-1,000 mg) have been shown to actually lower blood cholesterol in high cholesterol patients receiving supplementation.

Currently about 50% of all deaths result from heart attacks, strokes and related vascular problems. It appears that vitamin C supplementation can play a significant role in the prevention of these problems in addition to its other widely known health benefits.

The recommended daily allowance for vitamin C is listed at 60 mg. This nominal amount of vitamin C is insufficient to raise blood levels into a more protective range, discouraging free radical damage to blood cholesterol and helping to lower the total amount of cholesterol in the bloodstream.

Unbelievably, 20-30% of U.S. adults fail to even attain 60 mg of vitamin C each day from their diet.

In my opinion, vitamin C is just too critical a nutrient to leave to chance. Even if your diet is good, most people will still only obtain 200-250 mg of vitamin C per day. For this reason, I continue to recommend 1,000 mg of vitamin C from supplementation for healthy adults.

It’s becoming more widely accepted that a number of vitamins work together to help maximize protection against heart disease and stroke. Those vitamins include vitamins E, C, B6, B12, B1, and folic acid.

References:

Harats, D. et al. Citrus fruit supplementation reduces lipoprotein oxidation in young men ingesting a diet high in saturated fat: presumptive evidence for an interaction between vitamin C and E in vivo.Am J ClinNutr. Feb 1998; 67:240-245

Gey, K.F. et al. Inverse correlation between plasma Vitamin E and mortality from ischemic heart disease in cross-cultural epidemiology. Am J ClinNutr. 1991; 53 (suppl):326s-34s.

Frei, B. Ascorbic acid protects lipids in human plasma and low-density lipoprotein against oxidative damage. Am J ClinNutr. 1991;54 (suppl):1113s-8s.

Knekt, P. et al. Antioxidant vitamin intake and coronary mortality in a longitudinal population study. Am J Epidemiol 1994;139:1180-9

Ginter, E. et al. The effect of ascorbic acid on cholesterolemia in healthy subjects with seasonal deficit of vitamin C. NutrMetab 1970;12:76-86

Paolisso, G. et al. Metabolic benefits deriving from chronic vitamin C supplementation in aged non-insulin dependent diabetics. J Am Coll.Nutr.1995;14:387-92.