Vitamin clinical/epidemiological studies

This ambivalence has generated criticism against antioxidants because they may interfere with this protection derived from the oxidative processes. Antioxidant intakes have been analyzed during clinical/epidemiological studies, which focused usually on vitamin C and E, beta-carotene, and flavonoids, respectively, The results were a mixture of positive and negative outcomes. 

Tfcble 8 Some of the most important clinical/epidemiological studies using vitamin C in cardiovascular disease... 

A randomized controlled trial has indicated that vitamin E supplementation enhances certain clinically relevant in vivo indexes of T-cell-mediated fimction in healthy elderly persons [25]. In addition, epidemiologic studies suggest a number of benefits as a consequence of high intakes of a-tocopherol [26-29]. 

Different epidemiological studies suggest that raised plasma concentrations of total Hey may be a common, causal and treatable risk factor for athero-thromboembolic ischemic stroke. Therefore, a study aimed to assess the effect of Vitamins to Prevent Stroke (VITATOPS)—an international, multi-centre, randomized, double-blind, placebo-controlled clinical trial using a multivitamin therapy (folic acid 2 mg, vitamin Bg 25 mg, vitamin B12 500 pg) has been carried out. A total of 8000 patients were randomized and followed up for a mean period of 2.5 years (range 1-8 years) (VITATOPS Trial Study Group 2002). 

Elevated homocysteine concentrations have been associated with an increased risk for cardiovascular disease in both epidemiologic and clinical studies.43 Several studies have evaluated the benefit of lowering homocysteine levels with folic acid supplementation. One study reported a reduction in major cardiac events with the combination of folic acid, vitamin B12, and vitamin B6 following PCI.44 However, a more recent study found an increased risk of instent restenosis and the need for target-vessel revascularization with folate supplementation following coronary stent placement.45 The role of folate in the management of IHD is currently unclear. 

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