DETERMINATION OF OPTIMAL VITAMIN-C REQUIREMENTS IN HUMANS

Although the recommended dietary allowance provides an estimate for vi tamin C ingestion in humans, optimal vitamin C requirements are unknow n. We define optimal vitamin C requirements operationally based on the following: dose-function relations, availability in the food supply, steady state concentrations in plasma and tissues achieved at each dos e of vitamin C, urinary excretion, bioavailability, toxicity, and epid emiologic observations. Optimal vitamin C requirements can be estimate d when information is available for at least some of these criteria.