caa a22 4500 388097051 CHVBK 20180307125306.0 cr unu---uuuuu 161130e199905 xx s 000 0 eng 10.1017/S0029665199000567 doi S0029665199000567 pii (NATIONALLICENCE)cambridge-10.1017/S0029665199000567 Bender David A. Department of Biochemistry and Molecular Biology, University College London, Gower Street, London WC1E 6BT, UK Optimum nutrition: thiamin, biotin and pantothenate [Elektronische Daten] [David A. Bender] The metabolism of glucose is deranged in thiamin deficiency, but once any deficiency has been corrected there is no further effect of increased thiamin intake on the ability to metabolize glucose through either pyruvate dehydrogenase (EC 1.2.4.1) and the citric acid cycle, or the pentose phosphate pathway, in which transketolase (EC 2.2.1.1) is the thiamin-dependent step. It has been suggested that the Wernicke-Korsakoff syndrome is associated with a genetic variant of transketolase which requires a higher than normal concentration of thiamin diphosphate for activity. This finding would suggest that there may be a group of the population who have a higher than average requirement for thiamin, but the evidence is not convincing. There are no estimates of biotin requirements, but either coenzyme saturation of erythrocyte pyruvate carboxylase, or the excretion of 3-hydroxy-isovalerate (perhaps after a test dose of leucine) could be used to assess requirements in depletion-repletion studies. Biotin deficiency leads to impaired glucose tolerance, but it is unlikely that glucose tolerance could be used to assess optimum biotin status, since other more common factors affect glucose tolerance to a greater extent. Plasma triacylglycerol and non-esterified fatty acids are moderately elevated in pantothenic acid deficiency. However, this is unlikely to be useful in assessing pantothenate status, since again, other more common factors affect plasma lipids. To date there are no biochemical indices of adequate pantothenate nutrition, and no estimates of requirements. Copyright © The Nutrition Society 1999 Thiamin status nationallicence Biotin status nationallicence Pantothenate status nationallicence Transketolase activation nationallicence Erythrocyte pyruvate carboxylase nationallicence 3-Hydroxy-isovalerate excretion nationallicence Proceedings of the Nutrition Society Cambridge University Press 58/2(1999-05), 427-433 0029-6651 58:2<427 1999 58 PNS https://doi.org/10.1017/S0029665199000567 text/html Onlinezugriff via DOI 1 conference jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S0029665199000567 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Bender David A. Department of Biochemistry and Molecular Biology, University College London, Gower Street, London WC1E 6BT, UK NATIONALLICENCE 773 0- Proceedings of the Nutrition Society Cambridge University Press 58/2(1999-05), 427-433 0029-6651 58:2<427 1999 58 PNS CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge