Artery disease can restrict normal blood flow and impair artery function, and is a common cause of poor circulation. People with a relatively high dietary intake of antioxidant compounds -- including some vitamins -- as part of a healthy diet containing fruits, vegetables and whole grains, may be at lower risk of developing disease in the heart arteries. Additionally, large supplemental doses of B vitamins such as folic acid and niacin are being investigated for treating poor circulation and improving artery function and blood flow. Large vitamin doses should only be taken under medical supervision, however.
Causes of Poor Circulation
Accumulation of fatty and degenerative plaque in artery walls can lead to artery narrowing and a type of artery disease called atherosclerosis -- one of the most common causes of poor circulation. Atherosclerosis in heart arteries can lead to a heart attack. In the carotid arteries of the neck that feed the brain, it may lead to cerebrovascular disease and stroke. Peripheral artery disease causes poor circulation in areas other than the heart and brain. Diabetes and abnormalities in fat and sugar metabolism are risk factors for atherosclerosis. One apparent mechanism for artery disease is called oxidative stress. It involves formation of compounds such as free radicals and oxidized fats in artery walls.
Vitamins C and E, as well as alpha- and beta-carotene, are antioxidant vitamins that could help reduce oxidative stress in artery walls. Clinical studies of the effects of supplemental use of antioxidant vitamins on artery disease have shown mixed results, however. For example, daily supplementation with 272 IU vitamin E plus 500 mg slow-release vitamin C for 6 years was shown to slow plaque development in carotid arteries, according to a study published in the February 25, 2003 issue of “Circulation.” In contrast, a study published in the February 18, 2004 issue of “Journal of the American College of Cardiology” found that supplementing the diet with 800 IU vitamin E plus 1,000 mg vitamin C daily for 6 months did not improve artery function in people with atherosclerosis. Supplementing the diet with antioxidant vitamins has not shown a clear benefit for reducing the risk of death from heart attack and stroke, according to the American Heart Association.
Artery disease can produce a loss of artery flexibility and reduced ability to expand, or dilate, with increases in blood flow. Experimental studies performed with tissues cultured outside the body indicate that folic acid enhances production of nitric oxide -- a compound that helps arteries to dilate -- in response to increased blood flow. Folic acid may also help lower artery tissue oxidative stress associated with atherosclerosis. An analysis of 14 clinical studies that was published in the September 2007 issue of “The American Journal of Clinical Nutrition” found that very high doses of 5 to 10 g folic acid/day for at least 4 weeks may improve artery dilation function.
Relatively large doses of niacin, or vitamin B3, are also being investigated for treating artery disease. A study appearing in the November 3, 2009 issue of “Journal of the American College of Cardiology” reported that 2 g niacin daily for 12 months reduced plaque formation in carotid arteries of people who were also taking statin drugs. In people with type 2 diabetes who were also taking statin drugs, 1.5 g niacin/day for 3 months was found to improve wrist artery dilation function, according to a study published in the January 5, 2010 issue of “Circulation.”