The Rate of Increase of Blood Plasma Ascorbic Acid after Ingestion of Ascorbic Acid (Vitamin C)

Abstract

Five subjects, studied for rate of increase in plasma ascorbic acid after ingestion of 50 mg. of this vitamin, showed close similarity in response for the different subjects and for the same subject at different times. The ascorbic acid content of blood plasma began to rise within 30 to 60 minutes after ingestion of 50 mg. of the vitamin either in crystalline form or from fruits, and returned to the fasting level in 3 to 4 hours. The maximum increase in plasma level of ascorbic acid was reached within 1½ hours after ingestion of 50 mg. of this substance in either the crystalline form, as orange juice, or as orange sections; in 2 hours when strawberries were the source of ascorbic acid; and in 2½ hours when cauliflower was eaten. The curve for increase of plasma ascorbic acid was not influenced by fat or by ferrous or ferric salt taken at the same time as the ascorbic acid. When the intake was raised to 400 mg. ascorbic acid there was a greater increase in plasma concentration and a longer time elapsed before returning to the original fasting level. Ingestion of 50 mg. ascorbic acid did not cause an increase in its plasma concentration when the fasting level was 0.5 mg. or less per 100 ml. plasma.