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Vitamin C and Human Health Vitamin C and Human Health Edited by Anitra C. Carr and Margreet M.C. Vissers Printed Edition of the Special Issue Published in Nutrients www.mdpi.com/journal/nutrients Anitra C. Carr and Margreet M.C. Vissers (Eds.) Vitamin C and Human Health This book is a reprint of the special issue that appeared in the online open access journal Nutrients (ISSN 2072-6643) in 2013 (available at: http://www.mdpi.com/journal/nutrients/special_issues/vitamin_C_and_human_health). Guest Editors Anitra C. Carr Research Fellow & Centre Co-ordinator, Centre for Free Radical Research, Department of Pathology, University of Otago Christchurch 8140, New Zealand Margreet C. M. Vissers Professor & Associate Dean (Research), Centre for Free Radical Research, Department of Pathology, University of Otago Christchurch 8140, New Zealand Editorial Office MDPI AG Klybeckstrasse 64 Basel, Switzerland Publisher Shu-Kun Lin Production Editor Martyn Rittman 1. Edition 2014 MDPI • Basel • Beijing ISBN 978-3-906980-62-1 © 2014 by the authors; licensee MDPI, Basel, Switzerland. All articles in this volume are Open Access distributed under the Creative Commons Attribution 3.0 license (http://creativecommons.org/licenses/by/3.0/), which allows users to download, copy and build upon published articles even for commercial purposes, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications. However, the dissemination and distribution of copies of this book as a whole is restricted to MDPI, Basel, Switzerland. III Table of Contents Anitra C. Carr and Margreet M.C. Vissers Preface Guest Editors ................................................................................................................ V 1. Methodology Overview Alexander J. Michels and Balz Frei Myths, Artifacts, and Fatal Flaws: Identifying Limitations and Opportunities in Vitamin C Research Nutrients 2013, 5(12), 5161-5192 .............................................................................................. 1 http://www.mdpi.com/2072-6643/5/12/5161 2. Cancer & Inflammation Seyeon Park The Effects of High Concentrations of Vitamin C on Cancer Cells Nutrients 2013, 5(9), 3496-3505 .............................................................................................. 33 http://www.mdpi.com/2072-6643/5/9/3496 Amaya Azqueta, Solange Costa, Yolanda Lorenzo, Nasser E. Bastani and Andrew R. Collins Vitamin C in Cultured Human (HeLa) Cells: Lack of Effect on DNA Protection and Repair Nutrients 2013, 5(4), 1200-1217 .............................................................................................. 43 http://www.mdpi.com/2072-6643/5/4/1200 Bassem M. Mohammed, Bernard J. Fisher, Donatas Kraskauskas, Daniela Farkas, Donald F. Brophy, Alpha A. Fowler and Ramesh Natarajan Vitamin C: A Novel Regulator of Neutrophil Extracellular Trap Formation Nutrients 2013, 5(8), 3131-3150 .............................................................................................. 61 http://www.mdpi.com/2072-6643/5/8/3131 3. Neurological Effects Fiona E. Harrison, Gene L. Bowman and Maria Cristina Polidori Ascorbic Acid and the Brain: Rationale for the Use against Cognitive Decline Nutrients 2014, 6(4), 1752-1781 .............................................................................................. 81 http://www.mdpi.com/2072-6643/6/4/1752 IV Naohiro Iwata, Mari Okazaki, Meiyan Xuan, Shinya Kamiuchi, Hirokazu Matsuzaki and Yasuhide Hibino Orally Administrated Ascorbic Acid Suppresses Neuronal Damage and Modifies Expression of SVCT2 and GLUT1 in the Brain of Diabetic Rats with Cerebral Ischemia-Reperfusion Nutrients 2014, 6(4), 1554-1577 ............................................................................................ 111 http://www.mdpi.com/2072-6643/6/4/1554 4. Bioavailability Anitra C. Carr and Margreet C. M. Vissers Synthetic or Food-Derived Vitamin C—Are They Equally Bioavailable? Nutrients 2013, 5(11), 4284-4304 .......................................................................................... 134 http://www.mdpi.com/2072-6643/5/11/4284 Anitra C. Carr, Stephanie M. Bozonet, Juliet M. Pullar, Jeremy W. Simcock and Margreet C. M. Vissers A Randomized Steady-State Bioavailability Study of Synthetic versus Natural (Kiwifruit- Derived) Vitamin C Nutrients 2013, 5(9), 3684-3695 ............................................................................................ 155 http://www.mdpi.com/2072-6643/5/9/3684 Anitra C. Carr, Stephanie M. Bozonet and Margreet C. M. Vissers A Randomised Cross-Over Pharmacokinetic Bioavailability Study of Synthetic versus Kiwifruit-Derived Vitamin C Nutrients 2013, 5(11), 4451-4461 .......................................................................................... 166 http://www.mdpi.com/2072-6643/5/11/4451 5. Human Requirements Joris R. Delanghe, Marc L. De Buyzere, Marijn M. Speeckaert and Michel R. Langlois Genetic Aspects of Scurvy and the European Famine of 1845–1848 Nutrients 2013, 5(9), 3582-3588 ............................................................................................ 177 http://www.mdpi.com/2072-6643/5/9/3582 Maiken Lindblad, Pernille Tveden-Nyborg and Jens Lykkesfeldt Regulation of Vitamin C Homeostasis during Deficiency Nutrients 2013, 5(8), 2860-2879 ............................................................................................ 183 http://www.mdpi.com/2072-6643/5/8/2860 Daniel R. Gallie Increasing Vitamin C Content in Plant Foods to Improve Their Nutritional Value—Successes and Challenges Nutrients 2013, 5(9), 3424-3446 ............................................................................................ 203 http://www.mdpi.com/2072-6643/5/9/3424 V Preface Ascorbic acid is a small, simple, water soluble molecule, synthesised by most plants and animals, with the exception of humans and some animal species due to mutations in the gene encoding the terminal enzyme in the biosynthetic pathway. For humans, it is thus a vitamin (vitamin C) that must be obtained from the diet, with complete deficiency resulting in the fatal disease scurvy. Many functions have been attributed to this fascinating molecule and, despite nearly 90 years of research since its discovery, new roles are still being uncovered, including recent discoveries that it acts as a regulator of epigenetic marks and transcription factors (1). In this volume we begin with a review by Michels and Frei on specific factors that need to be taken into consideration when carrying out vitamin C research. Translational research normally comprises a progression from in vitro/cell culture studies to animal models and finally to clinical trials. At each of these stages, there are requirements specific to vitamin C research that need to be integrated into study designs and this review describes these in detail. Although normal vitamin C intake in humans is via ingestion, in the past decades there has been a surge of interest in the effects of intravenous administration of supra-physiological doses of vitamin C. This is particularly common in the treatment of cancer, and is an area of great controversy (2), most of which can be attributed to the lack of an agreed mechanism of action and numerous issues around study design, including a lack of understanding of vitamin C pharmacokinetics (3). Vitamin C administered intravenously bypasses the regulated intestinal uptake mechanism and results in significantly higher plasma concentrations than are obtained through oral intake. It is proposed that, at these high doses, vitamin C acts as a pro- drug via metal ion-dependent generation of cytotoxic hydrogen peroxide, although other potential anticancer mechanisms are also possible (1). In the contribution by Park, pharmacologic studies of the effects of high dose vitamin C on cancer cells are reviewed. In addition, Azqueta et al. have investigated the pro- and anti-oxidant effects of vitamin C on DNA damage and repair in cultured cervical cancer cells. High dose vitamin C has also been shown to improve the outcomes of patients with sepsis (4). In their contribution, Mohammed et al. used a knockout murine model to investigate the effect of parenteral vitamin C on neutrophil extracellular trap formation, autophagy and apoptosis, in experimentally induced sepsis. The highest levels of vitamin C in the body are found in the brain and neuroendocrine tissue. The brain is also relatively resistant to vitamin C depletion, indicating a vital role for the vitamin. Vitamin C likely has many functions in the brain (5), including acting as a cofactor for monooxygenase-dependent synthesis of neurotransmitters and neuropeptide hormones, as well as recycling of the enzyme cofactor tetrahydrobiopterin. In their contribution, Harrison et al. review the role for vitamin C in the aging brain, covering vitamin C transport, animal studies, and human studies that suggest potential usefulness of vitamin C against cognitive decline. Iwata et al. have investigated the anti-inflammatory and anti- apoptotic effects of vitamin C in the brains of diabetic rats with cerebral ischemia-reperfusion. They also reported vitamin C-dependent regulation of the vitamin C transporter SVCT2, the transporter isoform responsible for vitamin C uptake in neuronal tissue (5). Early vitamin C research, particularly in animal models, indicated that food-derived vitamin C may have enhanced bioavailability compared with synthetic vitamin C. This was attributed to the presence of plant-derived bio-flavonoids. We recently
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