COMPARISON OF VITAMIN-C BIOAVAILABILITY AFTER MULTIPLE OR SINGLE ORALDOSING OF DIFFERENT FORMULATIONS IN SHEEP

The purpose of this study was to compare the bioavailability of either multiple or single oral supplementation of different formulations of vitamin C and intra-duodenal supplementation of one form of vitamin C in sheep. Formulations used in the study were (1) ascorbic acid fine p owder (AA); (2) ascorbic acid coated with ethyl cellulose (EC), (3) Ro vimix STAY-C (SC); (4) sodium ascorbate (SA); (5) Rovimix C (RC). The bioavailability of vitamin C formulations was assessed by the changes in plasma ascorbic acid concentrations, area under the curve (AUG) and area under the curve above its basal concentration (AUC(above)) value s. There was no effect of single oral supple mentation on bioavailabil ity of vitamin C. Multiple dosing over a period of 28 days of oral sup plementation of all five formulations resulted in higher AUC(above) va lues. Furthermore, multiple oral supplementation of RC increased plasm a concentrations of ascorbic acids and AUC values. Single intra-duoden al supplementation of ascorbic acid resulted in significantly higher A UC when compared with oral supplementation of the same vitamin C.