Vitamin E: Food Chemistry, Composition, And Analysis
Vitamin ECopyright 2004 by Marcel Dekker, Inc.
FOOD SCIENCE AND TECHNOLOGYA Series of Monographs, Textbooks, and Reference BooksEDITORIAL BOARDSenior EditorsOwen R.Fennema University of Wisconsin-MadisonY.H.Hui Science Technology SystemMarcus Karel Rutgers University (emeritus)Pieter Walstra Wageningen UniversityJohn R.Whitaker University of California-DavisAdditives P.Michael Davidson University of Tennessee-KnoxvilleDairy science James L.Steele University of Wisconsin-MadisonFlavor chemistry and sensory analysis John H.Thorngate III Universityof California-DavisFood engineering Daryl B.Lund University of Wisconsin-MadisonFood lipids and flavors David B.Min Ohio State UniversityFood proteins/food chemistry Rickey Y.Yada University of GuelphHealth and disease Seppo Salminen University of Turku, FinlandNutrition and nutraceuticals Mark Dreher Mead Johnson NutritionalsPhase transition/food microstructure Richard W.Hartel University ofWisconsin-MadisonProcessing and preservation Gustavo V.Barbosa-Cánovas WashingtonState University-PullmanSafety and toxicology Sanford Miller University of Texas-Austin1. Flavor Research: Principles and Techniques, R.Teranishi, I.Hornstein,P.Issenberg, and E.L.Wick2. Principles of Enzymology for the Food Sciences, John R.Whitaker3. Low-Temperature Preservation of Foods and Living Matter, Owen R.Fennema, William D.Powrie, and Elmer H.Marth4. Principles of Food SciencePart I: Food Chemistry, edited by Owen R.FennemaPart II: Physical Principles of Food Preservation, Marcus Karel, OwenR.Fennema, and Daryl B.Lund5. Food Emulsions, edited by Stig E.Friberg6. Nutritional and Safety Aspects of Food Processing, edited by StevenR.Tannenbaum7. Flavor Research: Recent Advances, edited by R.Teranishi, Robert A.Flath, and Hiroshi Sugisawa8. Computer-Aided Techniques in Food Technology, edited by IsraelSaguyCopyright 2004 by Marcel Dekker, Inc.
9. Handbook of Tropical Foods, edited by Harvey T.Chan10. Antimicrobials in Foods, edited by Alfred Larry Branen and P.MichaelDavidson11. Food Constituents and Food Residues: Their ChromatographicDetermination, edited by James F.Lawrence12. Aspartame: Physiology and Biochemistry, edited by Lewis D.Stegink andL.J.Filer, Jr.13. Handbook of Vitamins: Nutritional, Biochemical, and Clinical Aspects,edited by Lawrence J.Machlin14. Starch Conversion Technology, edited by G.M.A.van Beynum and J.A.Roels15. Food Chemistry: Second Edition, Revised and Expanded, edited byOwen R.Fennema16. Sensory Evaluation of Food: Statistical Methods and Procedures, MichaelO’Mahony17. Alternative Sweeteners, edited by Lyn O’Brien Nabors and Robert C.Gelardi18. Citrus Fruits and Their Products: Analysis and Technology, S.V.Ting andRussell L.Rouseff19. Engineering Properties of Foods, edited by M.A.Rao and S.S.H. Rizvi20. Umami: A Basic Taste, edited by Yojiro Kawamura and Morley R. Kare21. Food Biotechnology, edited by Dietrich Knorr22. Food Texture: Instrumental and Sensory Measurement, edited by HowardR.Moskowitz23. Seafoods and Fish Oils in Human Health and Disease, John E. Kinsella24. Postharvest Physiology of Vegetables, edited by J.Weichmann25. Handbook of Dietary Fiber: An Applied Approach, Mark L.Dreher26. Food Toxicology, Parts A and B, Jose M.Concon27. Modern Carbohydrate Chemistry, Roger W.Binkley28. Trace Minerals in Foods, edited by Kenneth T.Smith29. Protein Quality and the Effects of Processing, edited by R.Dixon Phillipsand John W.Finley30. Adulteration of Fruit Juice Beverages, edited by Steven Nagy, John A.Attaway, and Martha E.Rhodes31. Foodborne Bacterial Pathogens, edited by Michael P.Doyle32. Legumes: Chemistry, Technology, and Human Nutrition, edited by RuthH.Matthews33. Industrialization of Indigenous Fermented Foods, edited by Keith H.Steinkraus34. International Food Regulation Handbook: Policy Science Law, editedby Roger D.Middlekauff and Philippe Shubik35. Food Additives, edited by A.Larry Branen, P.Michael Davidson, andSeppo Salminen36. Safety of Irradiated Foods, J.F.DiehlCopyright 2004 by Marcel Dekker, Inc.
37. Omega-3 Fatty Acids in Health and Disease, edited by Robert S.Leesand Marcus Karel38. Food Emulsions: Second Edition, Revised and Expanded, edited by KåreLarsson and Stig E.Friberg39. Seafood: Effects of Technology on Nutrition, George M.Pigott and BarbeeW.Tucker40. Handbook of Vitamins: Second Edition, Revised and Expanded, editedby Lawrence J.Machlin41. Handbook of Cereal Science and Technology, Klaus J.Lorenz and KarelKulp42. Food Processing Operations and Scale-Up, Kenneth J.Valentas, LeonLevine, and J.Peter Clark43. Fish Quality Control by Computer Vision, edited by L.F.Pau and R. Olafsson44. Volatile Compounds in Foods and Beverages, edited by Henk Maarse45. Instrumental Methods for Quality Assurance in Foods, edited by DanielY.C.Fung and Richard F.Matthews46. Listeria, Listeriosis, and Food Safety, Elliot T.Ryser and Elmer H. Marth47. Acesulfame-K, edited by D.G.Mayer and F.H.Kemper48. Alternative Sweeteners: Second Edition, Revised and Expanded, editedby Lyn O’Brien Nabors and Robert C.Gelardi49. Food Extrusion Science and Technology, edited by Jozef L.Kokini, ChiTang Ho, and Mukund V.Karwe50. Surimi Technology, edited by Tyre C.Lanier and Chong M.Lee51. Handbook of Food Engineering, edited by Dennis R.Heldman and DarylB.Lund52. Food Analysis by HPLC, edited by Leo M.L.Nollet53. Fatty Acids in Foods and Their Health Implications, edited by ChingKuang Chow54. Clostridium botulinum: Ecology and Control in Foods, edited by AndreasH.W.Hauschild and Karen L.Dodds55. Cereals in Breadmaking: A Molecular Colloidal Approach, Ann-CharlotteEliasson and Kåre Larsson56. Low-Calorie Foods Handbook, edited by Aaron M.Altschul57. Antimicrobials in Foods: Second Edition, Revised and Expanded, editedby P.Michael Davidson and Alfred Larry Branen58. Lactic Acid Bacteria, edited by Seppo Salminen and Atte von Wright59. Rice Science and Technology, edited by Wayne E.Marshall and JamesI.Wadsworth60. Food Biosensor Analysis, edited by Gabriele Wagner and George G.Guilbault61. Principles of Enzymology for the Food Sciences: Second Edition, JohnR.Whitaker62. Carbohydrate Polyesters as Fat Substitutes, edited by Casimir C. Akohand Barry G.SwansonCopyright 2004 by Marcel Dekker, Inc.
63. Engineering Properties of Foods: Second Edition, Revised andExpanded, edited by M.A.Rao and S.S.H.Rizvi64. Handbook of Brewing, edited by William A.Hardwick65. Analyzing Food for Nutrition Labeling and Hazardous Contaminants,edited by lke J.Jeon and William G.Ikins66. Ingredient Interactions: Effects on Food Quality, edited by AnilkumarG.Gaonkar67. Food Polysaccharides and Their Applications, edited by Alistair M. Stephen68. Safety of Irradiated Foods: Second Edition, Revised and Expanded, J.F.Diehl69. Nutrition Labeling Handbook, edited by Ralph Shapiro70. Handbook of Fruit Science and Technology: Production, Composition,Storage, and Processing, edited by D.K.Salunkhe and S.S.Kadam71. Food Antioxidants: Technological, Toxicological, and Health Perspectives,edited by D.L.Madhavi, S.S.Deshpande, and D.K.Salunkhe72. Freezing Effects on Food Quality, edited by Lester E.Jeremiah73. Handbook of Indigenous Fermented Foods: Second Edition, Revised andExpanded, edited by Keith H.Steinkraus74. Carbohydrates in Food, edited by Ann-Charlotte Eliasson75. Baked Goods Freshness: Technology, Evaluation, and Inhibition ofStaling, edited by Ronald E.Hebeda and Henry F.Zobel76. Food Chemistry: Third Edition, edited by Owen R.Fennema77. Handbook of Food Analysis: Volumes 1 and 2, edited by Leo M.L. Nollet78. Computerized Control Systems in the Food Industry, edited by GauriS.Mittal79. Techniques for Analyzing Food Aroma, edited by Ray Marsili80. Food Proteins and Their Applications, edited by Srinivasan Damodaranand Alain Paraf81. Food Emulsions: Third Edition, Revised and Expanded, edited by StigE.Friberg and Kåre Larsson82. Nonthermal Preservation of Foods, Gustavo V.Barbosa-Cánovas, UshaR.Pothakamury, Enrique Palou, and Barry G.Swanson83. Milk and Dairy Product Technology, Edgar Spreer84. Applied Dairy Microbiology, edited by Elmer H.Marth and James L. Steele85. Lactic Acid Bacteria: Microbiology and Functional Aspects: SecondEdition, Revised and Expanded, edited by Seppo Salminen and Atte vonWright86. Handbook of Vegetable Science and Technology: Production,Composition, Storage, and Processing, edited by D.K.Salunkhe andS.S.Kadam87. Polysaccharide Association Structures in Food, edited by Reginald H. Walter88. Food Lipids: Chemistry, Nutrition, and Biotechnology, edited by CasimirC.Akoh and David B.Min89. Spice Science and Technology, Kenji Hirasa and Mitsuo TakemasaCopyright 2004 by Marcel Dekker, Inc.
90. Dairy Technology: Principles of Milk Properties and Processes, P. Walstra,T.J.Geurts, A.Noomen, A.Jellema, and M.A.J.S.van Boekel91. Coloring of Food, Drugs, and Cosmetics, Gisbert Otterstätter92. Listeria, Listeriosis, and Food Safety: Second Edition, Revised andExpanded, edited by Elliot T.Ryser and Elmer H.Marth93. Complex Carbohydrates in Foods, edited by Susan Sungsoo Cho, LeonProsky, and Mark Dreher94. Handbook of Food Preservation, edited by M.Shafiur Rahman95. International Food Safety Handbook: Science, International Regulation,and Control, edited by Kees van der Heijden, Maged Younes, LawrenceFishbein, and Sanford Miller96. Fatty Acids in Foods and Their Health Implications: Second Edition,Revised and Expanded, edited by Ching Kuang Chow97. Seafood Enzymes: Utilization and Influence on Postharvest SeafoodQuality, edited by Norman F.Haard and Benjamin K.Simpson98. Safe Handling of Foods, edited by Jeffrey M.Farber and Ewen C.D. Todd99. Handbook of Cereal Science and Technology: Second Edition, Revisedand Expanded, edited by Karel Kulp and Joseph G.Ponte, Jr.100. Food Analysis by HPLC: Second Edition, Revised and Expanded, editedby Leo M.L.Nollet101. Surimi and Surimi Seafood, edited by Jae W.Park102. Drug Residues in Foods: Pharmacology, Food Safety, and Analysis,Nickos A.Botsoglou and Dimitrios J.Fletouris103. Seafood and Freshwater Toxins: Pharmacology, Physiology, andDetection, edited by Luis M.Botana104. Handbook of Nutrition and Diet, Babasaheb B.Desai105. Nondestructive Food Evaluation: Techniques to Analyze Properties andQuality, edited by Sundaram Gunasekaran106. Green Tea: Health Benefits and Applications, Yukihiko Hara107. Food Processing Operations Modeling: Design and Analysis, edited byJoseph Irudayaraj108. Wine Microbiology: Science and Technology, Claudio Delfini and JosephV.Formica109. Handbook of Microwave Technology for Food Applications, edited byAshim K.Datta and Ramaswamy C.Anantheswaran110. Applied Dairy Microbiology: Second Edition, Revised and Expanded,edited by Elmer H.Marth and James L.Steele111. Transport Properties of Foods, George D.Saravacos and ZachariasB.Maroulis112. Alternative Sweeteners: Third Edition, Revised and Expanded, edited byLyn O’Brien Nabors113. Handbook of Dietary Fiber, edited by Susan Sungsoo Cho and MarkL.Dreher114. Control of Foodborne Microorganisms, edited by Vijay K.Juneja and JohnN.SofosCopyright 2004 by Marcel Dekker, Inc.
115. Flavor, Fragrance, and Odor Analysis, edited by Ray Marsili116. Food Additives: Second Edition, Revised and Expanded, edited by A.Larry Branen, P.Michael Davidson, Seppo Salminen, and John H.Thorngate, III117. Food Lipids: Chemistry, Nutrition, and Biotechnology: Second Edition,Revised and Expanded, edited by Casimir C.Akoh and David B.Min118. Food Protein Analysis: Quantitative Effects on Processing, R.K. OwusuApenten119. Handbook of Food Toxicology, S.S.Deshpande120. Food Plant Sanitation, edited by Y.H.Hui, Bernard L.Bruinsma, J. RichardGorham, Wai-Kit Nip, Phillip S.Tong, and Phil Ventresca121. Physical Chemistry of Foods, Pieter Walstra122. Handbook of Food Enzymology, edited by John R.Whitaker, AlphonsG.J.Voragen, and Dominic W.S.Wong123. Postharvest Physiology and Pathology of Vegetables: Second Edition,Revised and Expanded, edited by Jerry A.Bartz and Jeffrey K.Brecht124. Characterization of Cereals and Flours: Properties, Analysis, andApplications, edited by Gönül Kaletunç and Kenneth J.Breslauer125. International Handbook of Foodborne Pathogens, edited by MarianneD.Miliotis and Jeffrey W.Bier126. Food Process Design, Zacharias B.Maroulis and George D.Saravacos127. Handbook of Dough Fermentations, edited by Karel Kulp and KlausLorenz128. Extraction Optimization in Food Engineering, edited by Constantina Tziaand George Liadakis129. Physical Principles of Food Preservation: Second Edition, Revised andExpanded, Marcus Karel and Daryl B.Lund130. Handbook of Vegetable Preservation and Processing, edited by Y.H. Hui,Sue Ghazala, Dee M.Graham, K.D.Murrell, and Wai-Kit Nip131. Handbook of Flavor Characterization: Sensory Analysis, Chemistry, andPhysiology, edited by Kathryn D.Deibler and Jeannine Delwiche132. Food Emulsions: Fourth Edition, Revised and Expanded, edited by StigE.Friberg, Kåre Larsson, and Johan Sjöblom133. Handbook of Frozen Foods, edited by Y.H.Hui, Paul Cornillon, IsabelGuerrero Legarreta, Miang H.Lim, K.D.Murrell, and Wai-Kit Nip134. Handbook of Food and Beverage Fermentation Technology, edited byY.H.Hui, Lisbeth Meunier-Goddik, Åse Solvejg Hansen, Jytte Josephsen,Wai-Kit Nip, Peggy S.Stanfield, and Fidel Toldrá135. Genetic Variation in Taste Sensitivity, edited by John Prescott and BeverlyJ.Tepper136. Industrialization of Indigenous Fermented Foods: Second Edition,Revised and Expanded, edited by Keith H.Steinkraus137. Vitamin E: Food Chemistry, Composition, and Analysis, RonaldEitenmiller and Junsoo LeeCopyright 2004 by Marcel Dekker, Inc.
138. Handbook of Food Analysis: Second Edition, Revised and Expanded:Volumes 1, 2, and 3, edited by Leo M.L.Nollet139. Lactic Acid Bacteria: Microbiological and Functional Aspects, ThirdEdition, Revised and Expanded, edited by Seppo Salminen, Atte vonWright, and Arthur Ouwehand140. Fat Crystal Networks, Alejandro G.Marangoni141. Novel Food Processing Technologies, edited by Gustavo V.BarbosaCánovas, M.Soledad Tapia, and M.Pilar CanoAdditional Volumes in PreparationCopyright 2004 by Marcel Dekker, Inc.
Vitamin EFood Chemistry, Composition,and AnalysisRonald EitenmillerUniversity of GeorgiaAthens, Georgia, U.S.A.Junsoo LeeChungbuk National UniversityChungbuk, KoreaMARCEL DEKKER INC.Copyright 2004 by Marcel Dekker, Inc.N EW Y ORK BASEL
Although great care has been taken to provide accurate and current information, neither theauthor(s) nor the publisher, nor anyone else associated with this publication, shall be liablefor any loss, damage, or liability directly or indirectly caused or alleged to be caused bythis book. The material contained herein is not intended to provide specific advice orrecommendations for any specific situation.Trademark notice: Product or corporate names may be trademarks or registeredtrademarks and are used only for identification and explanation without intent to infringe.Library of Congress Cataloging-in-Publication DataA catalog record for this book is available from the Library of Congress.ISBN: 0-8247-0688-9This book is printed on acid-free paper.HeadquartersMarcel Dekker, Inc., 270 Madison Avenue, New York, NY 10016, U.S.A.tel: 212–696–9000; fax: 212–685–4540Distribution and Customer ServiceMarcel Dekker, Inc., Cimarron Road, Monticello, New York 12701, U.S.A.tel: 800–228–1160; fax: 845–796–1772Eastern Hemisphere DistributionMarcel Dekker AG, Hutgasse 4, Postfach 812, CH-4001 Basel, Switzerlandtel: 41–61–260–6300; fax: 41–61–260–6333World Wide Webhttp://www.dekker.comThe publisher offers discounts on this book when ordered in bulk quantities. For moreinformation, write to Special Sales/Professional Marketing at the headquarters addressabove.Copyright 2004 by Marcel Dekker, Inc. All Rights Reserved.Neither this book nor any part may be reproduced or transmitted in any form or by anymeans, electronic or mechanical, including photocopying, microfilming, and recording, orby any information storage and retrieval system, without permission in writing from thepublisher.Current printing (last digit):10 9 8 7 6 5 4 3 2 1PRINTED IN THE UNITED STATES OF AMERICACopyright 2004 by Marcel Dekker, Inc.
PrefaceKnowledge about vitamin E has expanded so rapidly over the past fewdecades that it is difficult for anyone to keep up with even a few of thegeneral areas pertinent to the vitamin—chemistry, nutrition, metabolism,genetics, functional impact on disease onset and severity, pharmacology,regulations, food technology, and food composition and analyticalchallenges, to name a few. Our careers in food science and technology arefocused on food composition and analysis. We have been privileged toplay a role in improving the availability of food composition informationon vitamin E and, in some ways, the analytical capability for its assay.Interaction with the food industry, the U.S. Department of AgricultureNutrient Data Laboratory, the U.S. Food and Drug Administration, andvarious international organizations concerned with food composition hasopened many avenues for research, none of which has been more satisfyingor challenging than work on vitamin E.The overall objective of this book is to provide insight into the vastbody of scientific information available on vitamin E related to foodscience and technology; thus, the emphasis is on food chemistry, foodcomposition, and food analysis. At the same time, these topics areintertwined with the food delivery system, basic nutrition, foodregulations, the functional food and pharmaceutical industries, and theexcellent efforts of scientists worldwide who are unraveling the subtletiesof vitamin E biochemistry. While our primary goal is to provide a resourceiiiCopyright 2004 by Marcel Dekker, Inc.
ivPrefaceuseful to food scientists, we hope scientists and students in others fieldswill find the book helpful.ACKNOWLEDGMENTThis book would not have been possible without the help of Ms. HuanHuan Huang, Dr. Lin Ye, and Dr. Ji-Yeon Chun. We sincerely thank themfor their diligent efforts.Ronald EitenmillerJunsoo LeeCopyright 2004 by Marcel Dekker, Inc.
ContentsPrefaceAbbreviations1. Vitamin E: Chemistry and Biochemistryiiivii12. Nutrition and Health Implications of Vitamin E393. Oxidation and the Role of Vitamin E as an Antioxidant in Foods894. Dietary Vitamin E Supplementation for Improvement of OxidativeStability of Muscle Foods, Milk, and Eggs1365. Stability of Vitamin E During Food Processing2316. Effects of Food Preparation and Storage on the Vitamin E Contentof Food2857. Analysis of Tocopherols and Tocotrienols in Foods3238. Food Composition—Vitamin E425vCopyright 2004 by Marcel Dekker, Inc.
List of µmMicrometerεMolar rienolα-TACall-rac-α-tocopheryl acetateα-TTPα-tocopherol transfer proteinAAcetoneACNAAtlanta Center for Nutrient Analysis, U.S. Food andDrug AdministrationviiCopyright 2004 by Marcel Dekker, Inc.
viiiList of AbbreviationsAIAdequate IntakeAIM-NDBSArchitecture and Integration Management, NutrientData Bank SystemAlCl3Aluminum -related macular degenerationAn Vp-Anisidine valueAOCSAmerican Oil Chemists’ SocietyAOMActive oxygen methodAREDSAge-Related Cataract and Vision Loss StudyASAPAntioxidant Supplementation in AtherosclerosisPrevention StudyATBCAlpha-Tocopherol, Beta Carotene Cancer PreventionStudyAVEDAtaxia with vitamin E deficiencyBF3Boron trifluorideBHAButylated hydroxyanisoleCCConfidence codeCECapillary electrophoresisCECCapillary electrochromatographyCFRCode of Federal RegulationsCHAOSCambridge Heart Antioxidant StudyCHCl3ChloroformCH2Cl2Methylene chlorideCLASCholesterol Lowering Atherosclerosis StudyCPSIICancer Prevention Study IICRMCertified reference materialCSFIIC
76. Food Chemistry: Third Edition, edited by Owen R.Fennema 77. Handbook of Food Analysis: Volumes 1 and 2, edited by Leo M.L. Nollet 78. Computerized Control Systems in the Food Industry, edited by Gauri S.Mittal 79. Techniques for Analyzing Food Aroma, edited by Ray Marsili 80. Food Proteins and Their Applications, edited by Srinivasan Damodaran
Konsumsi asam folat, vitamin B12 dan vitamin C pada ibu hamil tergolong masih rendah, sehingga konsumsi sumber vitamin perlu ditingkatkan untuk mencegah masalah selama kehamilan, seperti anemia, prematur, dan kematian ibu dan anak. Kata kunci: asam folat, ibu hamil, vitamin B12, vitamin C *Korespondensi: Telp: 628129192259, Surel: hardinsyah2010@gmail.com J. Gizi Pangan, Volume 12, Nomor 1 .
Milk Thistle Red Clover Rhodiola St. John’s Wort Soy Bean Tomato Tribulus Terrestris Willow Vitamin B1 Vitamin B2 Vitamin B6 Vitamin B12 Vitamin C Vitamin D3 Vitamin E MISCELLANEOUS Alpha Lipoic Acid Beta Carotene Caffeine Choline Bitartrate Chond. Sulphate Bovine Chond. Sulphate Porcine Ch
Normal vitamin D 36% 9% 55% Vitamin D deficiency* Severe vitamin D deficiency** Normal vitamin D Camargo CA, Jr., Ingham T, Wickens K, et al. Vitamin D status of newborns in New Zealand. Br J Nutr 2010;104:1051 -7. Grant CC, Wall CR, Crengle S, Scragg R. Vitamin D deficiency in early childhood Public Health Nutr. 2009;12(10):1893-1901
25-OH Vitamin D levels* To determine vitamin D status * Only measure if patient is symptomatic and has risk factors for Vitamin D deficiency. Measurement, status and management (see Appendix 1 for flowchart) Vitamin D level Vitamin D status Health effect Management 30 nmol/L Defi
VITAMIN A This vitamin helps your body maintain healthy eyes and skin. VITAMIN C This vitamin helps the body heal cuts and wounds and maintain healthy gums. VITAMIN E This vitamin helps maintain healthy cells throughout your body. WATER Water makes up more than half of your body weight. Your
important.1 But the form of the vitamin D in it is. Look for supplements that contain: Vitamin D3, which is superior at optimizing and maintaining vitamin D levels long-term2 3 Or, if you prefer a plant-based option: Vitamin D2, which is derived from yeast or mushrooms For best absorption, take vitamin D with a meal, especially one that .
vitamin D stores that are further depleted by the lack of vitamin D in maternal breastmilk. These children are at high risk of childhood rickets. Key aims of Vitamin D supplementation To ensure: 1. Maternal Vitamin D levels are replete to avoid neonatal rickets. 2. Vitamin D deficiency is reversed in a timely manner. 3.
VITAMIN D3 VITAMIN D2 Ergosterol Not produced in humans 1/3 activity D3 7-dehydrocholesterol Produced by skin by UVB Fully active 16 VITAMIN D3 1,25(OH) 2VITAMIN D 3 VITAMIN D3 Biologically inactive Does not bind to VDR Nutritional substance 1,25(OH) 2 D 3 Steroid hormone Acts through Vitamin D Receptor (VDR) 17
