Iowa State University Capstones, Theses and Graduate Theses and Dissertations Dissertations 2014 Models to assess food iron bioavailability Seth Mensah Armah Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/etd Part of the Human and Clinical Nutrition Commons Recommended Citation Armah, Seth Mensah, "Models to assess food iron bioavailability" (2014). Graduate Theses and Dissertations. 14085. https://lib.dr.iastate.edu/etd/14085 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Graduate Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. Models to assess food iron bioavailability by Seth Mensah Armah A dissertation submitted to the graduate faculty in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Major: Nutritional Sciences (Human Nutrition) Program of Study Committee: Manju Reddy, Co-Major Professor Alicia Carriquiry, Co-Major Professor James Hollis Wendy White Sarah Francis Iowa State University Ames, Iowa 2014 Copyright © Seth Mensah Armah, 2014. All rights reserved. ii TABLE OF CONTENTS Page LIST OF ABBREVIATIONS ......................................................................................... iv ACKNOWLEDGEMENTS ............................................................................................ vi ABSTRACT ..................................................................................................................... vii CHAPTER 1. GENERAL INTRODUCTION ................................................................1 Background ..................................................................................................................... 1 Objectives ........................................................................................................................ 2 Thesis Organization......................................................................................................... 3 References ....................................................................................................................... 3 CHAPTER 2. LITERATURE REVIEW .........................................................................5 Iron Absorption ............................................................................................................... 6 Iron Transport and Cellular Uptake ................................................................................ 8 Iron Storage ..................................................................................................................... 8 Regulation of Iron Storage and Uptake ......................................................................... 10 Ferritin and transferrin receptor ................................................................................. 10 The role of hepcidin in iron metabolism ................................................................... 11 Iron Utilization and Recycling ...................................................................................... 14 Functions of Iron ........................................................................................................... 15 DNA synthesis ........................................................................................................... 15 Iron and energy metabolism ...................................................................................... 16 Oxygen and electron transport ................................................................................... 16 Iron Deficiency and Anemia ......................................................................................... 17 Consequences of Iron Deficiency ................................................................................. 18 Adverse pregnancy outcome ..................................................................................... 19 Reduced work capacity and productivity .................................................................. 21 Assessment of Iron Nutritional Status ........................................................................... 22 Strategies to Address Iron Deficiency Anemia ............................................................. 24 Supplementation ........................................................................................................ 24 Fortification ............................................................................................................... 25 Food based approach ................................................................................................. 27 Estimating Prevalence of Inadequate Iron Intake ......................................................... 28 Iron Bioavailability ....................................................................................................... 32 Factors Influencing Iron Bioavailability ....................................................................... 33 Ascorbic acid ............................................................................................................. 33 Animal tissue ............................................................................................................. 35 Phytic acid ................................................................................................................. 36 iii Polyphenols ............................................................................................................... 38 Calcium ...................................................................................................................... 40 Estimating Iron Bioavailability ..................................................................................... 41 Chemical balance method .......................................................................................... 41 Solubility/dialyzability .............................................................................................. 42 Caco-2 cell model ...................................................................................................... 42 Isotopic methods ........................................................................................................ 44 Area under the curve for serum iron .......................................................................... 45 Algorithms ................................................................................................................. 46 Performance of Existing Algorithms in Predicting Iron Absorption from Diets .......... 50 Single vs. Complete Diet Absorption Studies ............................................................... 51 Conclusion ..................................................................................................................... 53 CHAPTER 3. A COMPLETE DIET BASED ALGORITHM FOR PREDICTING NONHEME IRON ABSORPTION IN ADULTS ..............................68 Abstract ......................................................................................................................... 68 Introduction ................................................................................................................... 69 Methods ......................................................................................................................... 70 Results ........................................................................................................................... 73 Discussion ..................................................................................................................... 74 References ..................................................................................................................... 78 CHAPTER 4. ESTIMATING IRON BIOAVAILABILITY FROM THE US DIET .....................................................................................................84 Abstract ......................................................................................................................... 84 Introduction ................................................................................................................... 85 Methods ......................................................................................................................... 88 Results ........................................................................................................................... 91 Discussion ..................................................................................................................... 92 References ..................................................................................................................... 97 CHAPTER 5. ADAPTATION OF IRON ABSORPTION IN HUMANS WITH HIGH PHYTATE DIET CONSUMPTION .................................105 Abstract ....................................................................................................................... 105 Introduction ................................................................................................................. 106 Methods ....................................................................................................................... 108 Results ......................................................................................................................... 112 Discussion ..................................................................................................................