title: Very low vitamin C activity of orally administered L-dehydroascorbic acid.
abstract: The biological activity of L-dehydroascorbic acid (DHA), which is easily formed from L-ascorbic acid (ASC) during storage and cooking processes, has been considered to be equivalent to that of ASC on the basis of studies made several decades ago, when a specific method to determine ASC was not available. The nutritional activity of orally ingested DHA has now been evaluated by comparing ASC concentrations in 12 tissues of rats administered four different doses of ASC. Determinations were made by using the specific and sensitive method, which had been developed by us. Here it is shown that the efficiency of DHA was almost 10% of that of ASC on a molar basis, based on animal experiments using the inherently scorbutic ODS rat, which is a convenient human model animal to investigate the metabolism of vitamin C. On the basis of these findings, it is proposed that it is necessary to reevaluate the nutritional requirement of vitamin C based on both ASC and DHA contents of foods.
authors.affiliation: Department of Food Science and Nutrition, Nara Women's University, Nara 630-8506, Japan.
authors.forename: Yukako
authors.initials: Y
authors.lastname: Ogiri
authors.forename: Fang
authors.initials: F
authors.lastname: Sun
authors.forename: Shoko
authors.initials: S
authors.lastname: Hayami
authors.forename: Aki
authors.initials: A
authors.lastname: Fujimura
authors.forename: Kinue
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Maki
authors.initials: M
authors.lastname: Yaita
authors.forename: Shosuke
authors.initials: S
authors.lastname: Kojo
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001205:Ascorbic Acid / Q000032:analysis*; D003683:Dehydroascorbic Acid / Q000008:administration & dosage / Q000493:pharmacokinetics*; D004195:Disease Models, Animal; D008297:Male; D009751:Nutritional Requirements; D009753:Nutritive Value; D051381:Rats; D012614:Scurvy / Q000188:drug therapy*; D014018:Tissue Distribution
chemical_list: D001205:Ascorbic Acid; D003683:Dehydroascorbic Acid