Vitamin Supplements

Table of Contents

• Vitamin Requirements
• Biology Poorly Established
• HIV-Related Deficiencies
• Diagnosis
• Table I: Core Foods for Vitamins
• Vitamin Supplementation
• Mega-Dosing
• Vitamin A and beta-Carotene
• Table II: Vitamin Toxicities
• Vitamin A and the Immune System
• Vitamin A and AIDS
• Vitamin B-6 (pyroxidine)
• Vitamin B-6 and Immunity
• Vitamin B-6 and AIDS
• Vitamin B-12 and Folate
• Folate / B-12 and Immunity
• Folate and Vitamin B-12 in AIDS
• Vitamin C
• Vitamin C and Immunity
• Vitamin C and Viral Diseases
• Vitamin C and AIDS
• Vitamin Discovery
• Bibliography

Vitamins are a diverse group of chemically unrelated compounds, present in food at minute levels, that are necessary for normal human function. By definition, the deficiency of a vitamin causes disease. Minerals are also critical to human life in minute amounts and they differ from vitamins only in that they are inorganic. (Organic in this case refers to the chemical meaning "composed of carbon," not "grown naturally" in the popular sense.) This article reviews basic background information on vitamins and minerals and examines several individual vitamins that are frequently discussed in the context of HIV.

Vitamin Requirements

An adequate diet supplies all required vitamin and minerals to a healthy individual. However, vitamins and minerals are unevenly distributed among different food sources. The 1976 Nationwide Food Consumption Survey estimated that most Americans obtain over 80 percent of their vitamin intake from 50 to 200 foods. As a result, several "core foods" have been identified that are particularly rich sources of vitamins. See Table 1

Vitamin and mineral requirements are established in the United States by the Recommended Daily Allowance (RDA) guidelines, a familiar item on food and dietary supplement labels. Contrary to popular belief, the RDA is not developed for prescriptive use nor do they establish target vitamin and mineral intakes for individuals. Wide individual variation exists in vitamin and mineral requirements. The RDA only provides standards for population studies of nutritional status and reference values for food labeling.

The RDA is the upper limit of a range of values which has a highest probability of fulfilling the nutritional requirements of most Americans. Any one individual may have a unique requirement within the range of intakes. There is a very small probability that an individual will have a required intake above the RDA level.¹ The RDA is established in populations of healthy, normal subjects. It is unknown if vitamin and mineral requirements differ substantially in a population of people with HIV, although infection may impact vitamin requirements, according to studies of other populations.