Ascorbic acid requirements of the trained monkey as determined by blood ascorbate levels.

: The ascorbate requirements of 4 monkeys were investigated by comparison of the plasma and whole blood ascorbate levels to known amounts of ascorbate supplements. The monkeys were conditioned to the experimental procedures to minimize environmental stress which increases ascorbate requirements. Trained monkeys required 3 and 6 mg AA/kg body weight fed daily to mature and young monkeys, respectively, to maintain blood ascorbate levels proposed as necessary to prevent the development of scurvy. Young monkeys (sexually immature) required twice the amount of the vitamin to maintain acceptable ascorbate levels than did the mature monkeys. Smaller amounts of ascorbate were required by the monkeys to maintain similar blood ascorbate levels when the vitamin was incorporated into the diet in comparison to the single and oral supplement. Only small variations were measured between the plasma and whole blood ascorbate levels in the same monkey. The leucocyte ascorbate levels suggest that the tissue ascorbate concentration may be minimal although the blood ascorbate concentration is in an acceptable range.