Although vitamin supplementation ma...

Although vitamin supplementation may be beneficial in patients with nutritional deficiencies (eg children, pregnant and lactating women the somewhat advanced in life patients with chronic illnesses), its usefulness in characters with healthy diets is les clear. any epidemiologic evidence indicates that dietary factors may have a causative character in the development of cancer and cardiovascular disease, making vitamin intake a potential focus. The U Preventive Services Task Force (USPSTF) reviewed prospective trials and observational studies forward the routine use of vitamin supplementation to obstruct cancer and cardiovascular disease.

According to the USPSTF, studies in succession the value of vitamin A alone in preventing cardiovascular disease have shown no positive issue Observational studies that demonstrate the utility of vitamin A in the prevention of colon and breast cancer have design issues that make the conclusions uncertain. Observational studies onward the effect of vitamin C onward cardiovascular disease have had inconsistent conclusions and have demonstrated no significant association between vitamin C supplementation and cancer risk. Vitamin E has not been shown to decrease the risk of cardiovascular disease or cancer. Beta-carotene does not decrease the risk of cancer or cardiovascular results Studies evaluating antioxidant vitamin combinations have been conflicting and indicate no consistent value. Other vitamin combinations have been studied if it were not that also provide no consistent benefit.

Vitamin supplys have been shown to have potential harms. Moderate doses of vitamin A may attenuate bone mineral density, and high doses can be teratogenic or hepatotoxic. Beta-carotene supplementation may be associated with increased mortality from lung cancer in smoker Because adverse efficiencys of vitamin supplementation rarely are reported in studies, the USPSTF notes that more studies are needed

The USPSTF judges that the evidence is inadequate to commit supplementation of vitamins A, C or E multivitamins with folic acid, or antioxidant combinations to decrease the risk of cancer or cardiovascular disease. Beta-carotene addition s should not be used routinely in asymptomatic patients, because there is no evidence of risk reduction and a certain number of evidence that the supplements may cause harm in a patient groups.

Berg AO and members of the U Preventive Services Task Force. Routine vitamin supplementation to obstruct cancer and cardiovascular disease: recommendations and rationale. Ann Intern M July 1 2003;139:51-5

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