Activity

Activity Description

In October 1998, the Institute of Medicine, through the Food and Nutrition Board (FNB) and the Standing Committee on the Scientific Evaluation of Dietary Reference Intakes, established a 14-member panel to (1) review the scientific literature regarding the dietary micronutrients, including vitamins A and K, iron, iodine, chromium, copper, manganese, molybdenum, zinc, other potentially beneficial trace elements such as boron to determine the roles, if any, they play in health; (2) review selected components of food that may influence the bioavailability of these compounds; (3) develop estimates of dietary intake of these compounds that are compatible with good nutrition throughout the life span and that may decrease risk of chronic disease where data indictate they play a role; (4) determine tolerable upper intake levels for each nutrient reviewed where adequate scientific data are available in specific population subgroups; and (5) identify research needed to improve the knowledge of the role of these micronutrients in health.

The panel met seven times, including twice in conjuction with workshops held to solicit the opinions of experts, practitioners and the public. Based on the analysis of scientific literature and evidence relating intake of micronutrients to reduction of the risk of chronic disease, and the daily amounts needed to maintain normal status based on the biochemical indicators and daily body losses, the panel's major findings and approaches include the following:

• One retinol activity equivalent (g RAE) is equal to 1 g all-trans-retinol, 12 g beta-carotene and 24 g alpha -carotene and beta-cryptoxanthin. The RAE for provitamin A carotenoids is two-fold higher than retinol equivalents (g RE), a change that means twice as much provitamin A-rich carotenoids contained in green leafy vegetables and certain fruits are required to provide a given amount of vitamin A. Given possible future changes in equivalency, weight of carotenoids should be given in food tables.
• RDAs for copper and molybdenum are established.
• Tolerable Upper Intake Levels (ULs) for vitamin A, boron, copper, iodine, iron, manganese, molybdenum, nickel, vanadium, and zinc are established.
• Research recommendations are made for information needed to advance understanding of human micronutrient requirements and the adverse effects.