Vitamin Supplementation.

It is generally considered that healthy persons eating a normal balanced diet should have no need for vitamin supplementation. A review of the topic pointed out that the vitamins that people chose foe self medication are often not the ones that are actually present in inadequate amounts in their diets and that the commercial preparations available often do not make it clear whether the amounts or many times greater. Supplementation should concentrate on groups of people at risk of deficiency such as neonate, who need vitamin K; pregnant and lactating women, who need calcium, folic acid, and iron; and certain groups, who need vitamin D; vegans and their infants may require vitamin B₁₂ supplements. A multivitamin supplement might be considered for some groups such as the elderly and those with reduced calorie intake. However, one might have difficulty in finding a good multivitamin preparation containing all 13 vitamins bit no non-vitamins. Also with many of the multivitamin preparation the doses and ratios varied inexplicably.

A review of supplementation specifically in children concluded that, provided school children and adolescents eat a wide variety of foods, there was no need for vitamin supplementation. However, it was recommended that supplementation with vitamins A, C, and D should be given to those between the ages of 6 month and 2 years and preferably up to the age of 5 years.

A subsequent study supports the suggestion that supplementation may be of some benefit in the elderly। Supplementation resulted in an improvement in immune response and a decreased frequency of infection in elderly subjects. It was suggested that dosage might be crucial and that excessive doses of micronutrients could impair rather than improve immune response.

Hypercholesterolemia is a major risk factor for the development of atherosclerosis and consequently ischemic heart disease. Since oxidation of lipids, particularly low-density-lipoprotein (LDL) cholesterol has been proposed as a factor in atherogenesis, the possibility of preventing atherosclerosis by the use of dietary antioxidants such as vitamin E and C and betacarotene has been investigated. Prospective epidemiological studies have revealed a reduced risk of ischemic heart disease in individuals taking vitamin E supplement, and those with a high carotene intake (particular smoker). In a further prospective cohort study, dietary vitamin E consumption, but not vitamin E supplementation, was associated with decreased risk of death from ischemic heart disease. Conversely, in these studies, intake of vitamin C did not appear to be associated with a decreased risk of ischemic heart disease. Data from some studies assessing serum or fat concentrations also provide evidence that high betacarotene concentrations are associated with decreased cardiovascular disease.