**14. Vitamins**

Vitamin C is a water-soluble vitamin and is believed to regenerate vitamin E from its oxi‐ dized state back to its activated state. The principal sources of vitamin C are citrus fruits, tomatoes and potatoes. Natural vitamin E is a mixture of tocopherols and tocotrienols syn‐ thesized only by plants and the natural sources are vegetal oils. In fact, olive oil contains vi‐ tamin E and many of its beneficial effects are attributed to this constituent.

Vitamin E acts as a chain-breaking anti-oxidant for LDL lipids [27]. *In vitro* enrichment of LDL in vitamin E drastically increases their resistance to oxidative stress and it has also been reported to inhibit the cytotoxicity of ox-LDL toward cultured endothelial cells. Vitamin E has been reported to retard atherosclerosis progression in certain arteries of primates fed an atherosclerosis diet. In humans, both women and men, exhibited reduced vascular disease parameters [75], beneficial effects in the reduction of risk of onset and progression of athero‐ sclerosis, due to its inhibition of LDL oxidation and association with molecular modulation of the interaction of immune and endothelial cells. A long term supplementation with vita‐ min E in hypercholesterolemic patients and/or chronic smokers increase levels of autoanti‐ bodies against ox-LDL. There is also a quite convincing evidence from *in vitro* studies that vitamin C strongly inhibits LDL oxidation [27].

It is important to underline that there are no definite recommendations on the dose and du‐ ration of supplementation with vitamins in human. Although, high dietary intake of fruit and vegetables is associated with a reduction in the incidence of atherosclerosis, stroke and cardiovascular mortality in general [27]. Moreover, epidemiologic studies have reported that high dietary intake of foods rich in vitamin E, vitamin C and *β*-carotene have been in‐ versely associated with the incidence of CVDs [35].

Actually, it is difficult to conclude that a clinical benefit of anti-oxidants in CVD is estab‐ lished. Thus, it is necessary to clarify why anti-oxidants showed their beneficial effects *in vitro*, whereas less satisfactory results were observed in some, although not all, clinical conditions [40].
