Vitamin B1 Thiamin.pdf

HNUT10010 HNUT10020 Human Nutrition 1: Understanding Nutrients Aifric O’Sullivan BSc, MSc, PhD UCD Institute of Food and Health School of Agriculture and Food Science Water Soluble B Group and C Water soluble vitamins Vitamin C Energy B complex vitamins Hematopoietic Other + Vitamin C Thiam...

HNUT10010 HNUT10020 Human Nutrition 1: Understanding Nutrients Aifric O’Sullivan BSc, MSc, PhD UCD Institute of Food and Health School of Agriculture and Food Science Water Soluble B Group and C Water soluble vitamins Vitamin C Energy B complex vitamins Hematopoietic Other + Vitamin C Thiamin (B1) Riboflavin (B2) Niacin (B3) Pantothenic acid (B5 ) Biotin (B7) Vitamin B6 (Pyridoxine) Folate (B9) Vitamin B12 Vitamin B6 Pantothenic acid (B5 ) Vitamin B6 (Pyridoxine) Thiamin (B1) Folate (B9) Vitamin B12 (Cobalamin) Niacin (B3) Vitamin B1 (Thiamin) hydroxyethyl side chain pyrimidine ring thiazole ring methylene bridge Thiamine diphosphate (TDP) The Nutrition Society Textbook Series, Introduction to Human Nutrition, Second Edition © 2009, 2002 Vitamin B1 Foods PRI 0.07-0.1mg/MJ Food Serving Thiamin (mg) Peas (cooked) 1/2 cup 0.21 Long grain brown rice (cooked) 1 cup 0.19 Long grain white rice, unenriched (cooked) 1 cup 0.04 Whole wheat bread 1 slice 0.10 White bread, enriched 1 slice 0.11 Fortified breakfast cereal 1 cup 0.5-2.0 Pork, lean (cooked) 3 ounces 0.72 Brazil nuts 1 ounce 0.18 Spinach (cooked) 1/2 cup 0.09 Orange 1 fruit 0.10 Milk 1 cup 0.10 Egg (cooked) 1 large 0.03 Vitamin B1 Metabolic Function • Energy metabolism – Thiamine diphosphate (TDP) (TPP) – Coenzyme role – Oxidative decarboxylation reactions • Synthesis DNA/RNA and NADPH (fatty acid synthesis) – Coenzyme role – Transketolase (enzyme in pentose phosphate pathway) • Nerve conduction – Non-coenzyme role – Needed for nerve membrane Na transport protein Vitamin B1 Metabolic Function Energy metabolism - oxidative decarboxylation Pyruvate Pyruvate dehydrogenase Acetyl-CoA Branch-chain keto-acid dehydrogenase involved in BCAA metabolism -ketoglutarate -ketoglutarate dehydrogenase succinyl-CoA Vitamin B1 Metabolic Function Vitamin B1 (Thiamin) Oedema associated with Wet Beriberi Vitamin B1 Deficiency • Beriberi (weakness) – Result of chronic deficiency and high carbohydrate intake • Dry Beriberi (nervous system) – Complains of weakness, stiffness and cramps in legs – As disease progresses muscle wasting and paralysis spread upward • Wet Beriberi (heart) – Arterioles dilate, fast blood flow and pulse – Heart failure and oedema Vitamin B1 Deficiency • Wernicke-Korsakoff syndrome – Usual presentation of deficiency in alcoholics – Central nervous system lesions 1. Korsakoff’s psychosis: loss of recent memory (confusion) 2. Wernicke's encephalopathy: effects vision Alcoholics Low thiamine intake (High carbohydrate intake) Effects absorption Liver damage Reading • Gibney M, Lanham-New S, Cassidy A, Vorster H, eds. Introduction to Human Nutrition. 2nd ed: Wiley-Blackwell, 2009. Chapter 8 • Gropper SS, Smith JL. Advanced Nutrition and Human Metabolism, International Edition 6th ed: Wadsworth Cenage Learning, 2013. Chapter 9/10 • Whitney E, Rolfes SR. Understanding Nutrition, 13th Edition: Wadsworth, Cengage Learning, 2013. Chapter 10/11