Human Nutrition 1: Understanding Nutrients 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 US RDA 320 mg women 420 mg men Magnesium Foods Whole-grains, legumes, green leafy vegetables good sources Food mg Wheat Bran,...

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 US RDA 320 mg women 420 mg men Magnesium Foods Whole-grains, legumes, green leafy vegetables good sources Food mg Wheat Bran, crude, ¼ cup Almonds, 1 ounce Spinach, cooked, ½ cup 89 80 78 Raisin bran cereal, 1 cup Bread, whole-wheat, 1 slice Avocado, cubes, ½ cup 77 23 22 Cheese Milk Yogurt 8-45 11-12 19 Magnesium Absorption and Metabolism Magnesium homeostasis is maintained by controlling intestinal absorption and losses in urine Small intestine 1 2 3 20-70% Passive Filtration Solvent drag Resorption 95% Water movement Active Regulated Magnesium Metabolic Function • >300 Enzyme reactions – Glucose  Pyruvate – β-oxidation of fatty acids (breakdown of fatty acids) – Protein synthesis • • • • • Bone development and maintenance (structure) DNA synthesis (gene transcription) ATP production (helps to stabilize anions) Muscle contraction and blood clotting Supports normal function of immune system Magnesium Deficiency and Toxicity • Deficiency – – – – Not a problem in healthy populations Complication of disease or rare genetic abnormality Hypocalcemia (blood) and hypocalciuria (urine) Abnormal neuromuscular function • Toxicity – Not observed from food intake – US tolerable UL 350 mg/day non-food forms – Changes in mental status, nausea, diarrhoea, appetite loss, muscle weakness, difficulty breathing, extremely low blood pressure, and irregular heartbeat Reading • Gibney M, Lanham-New S, Cassidy A, Vorster H, eds. Introduction to Human Nutrition. 2nd ed: Wiley-Blackwell, 2009. Chapter 9 • Gropper SS, Smith JL. Advanced Nutrition and Human Metabolism, International Edition 6th ed: Wadsworth Cenage Learning, 2013. Chapter 11-13 • Whitney E, Rolfes SR. Understanding Nutrition, 13th Edition: Wadsworth, Cengage Learning, 2013. Chapter 12-13