DOCSLIB.ORG

Vitamin B Status, Deficiency and Its Consequences

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Vitamin B Status, Deficiency and Its Consequences 03. VITAMIN B6 19/1/07 07:17 Página 7 Nutr Hosp. 2007;22(1):7-24 ISSN 0212-1611 • CODEN NUHOEQ S.V.R. 318 Revisión Vitamin B6 status, deficiency and its consequences - an overview A. Spinneker**, R. Sola*, V. Lemmen*,**, M. J. Castillo*, K. Pietrzik** and M. González-Gross*,**,*** *Grupo Effects 262. Facultad de Medicina. Universidad de Granada. Spain. **Institut für Ernährungs- und Lebensmittelwis- senschaften, Rheinische Friedrichs-Wilhelms Universität Bonn. Germany. ***Facultad de Ciencias de la Actividad Física y del Deporte. Universidad Politécnica de Madrid. Spain. Abstract ESTADO DE VITAMINA B6, DEFICIENCIA Y SUS CONSECUENCIAS — UNA REVISIÓN Background: Vitamin B6 is thought to be a most versa- tile coenzyme that participates in more than 100 bioche- mical reactions. It is involved in amino acid and ho- Resumen mocysteine metabolism, glucose and lipid metabolism, Antecedentes: se piensa que la vitamina B es la coenzi- neurotransmitter production and DNA/RNA synthesis. 6 Vitamin B can also be a modulator of gene expression. ma más versátil que participa en más de 100 reacciones 6 bioquímicas. Está implicada en el metabolismo de los Nowadays, clinically evident vitamin B6 deficiency is not a common disorder, at least in the general population. aminoácidos y de la homocisteína, el metabolismo de la Nevertheless, a subclinical, undiagnosed deficiency may glucosa y los lípidos, en la producción de neurotransmi- be present in some subjects, particularly in the elderly. sores y en la síntesis de ADN/ARN. Esta vitamina tam- Objective: This review gives a complete overview over bién puede ser un modulador de la expresión génica. the metabolism and interactions of vitamin B . Further, Hoy en día, la deficiencia clínicamente evidente de vita- 6 mina B no es una afección habitual, al menos en la po- we show which complications and deficiency symptoms 6 blación general. Sin embargo, puede ocurrir una defi- can occur due to a lack of vitamin B6 and possibilities for public health and supplemental interventions. ciencia subclínica no diagnosticada en algunos Methods: The database Medline (www.ncvi.nlm.nih.gov) individuos, especialmente en los ancianos. Objetivo: esta revisión aporta una visión de conjunto was searched for terms like “vitamin B6”, “pyridoxal”, “cancer”, “homocysteine”, etc. For a complete understan- completa sobre el metabolismo y las interacciones de la vitamina B . Además, mostramos qué complicaciones y ding, we included studies with early findings from the for- 6 ties as well as recent results from 2006. These studies were síntomas por deficiencia pueden ocurrir por la falta de vitamina B y las posibilidades de intervenciones de sa- summarised and compared in different chapters. 6 Results and conclusion: In fact, it has been proposed lud pública y de suplementos. that suboptimal vitamin B status is associated with cer- Métodos: se buscó en la base de datos Medline 6 (www.ncvi.nlm.nih.gov) con los términos “vitamin B ”, tain diseases that particularly afflict the elderly popula- 6 tion: impaired cognitive function, Alzheimer’s disease, “pyridoxal”, “cancer”, “homocysteine”, etc. Para una cardiovascular disease, and different types of cancer. So- mayor comprensión, incluimos estudios con hallazgos me of these problems may be related to the elevated ho- iniciales de los años cuarenta, así como estudios recientes del año 2006. Se resumieron estos estudios y se compara- mocysteine concentrations associated to vitamin B6 defi- ciency, but there is also evidence for other mechanisms ron por capítulos diferentes. independent of homocysteine by which a suboptimal vi- Resultados y conclusión: de hecho, se ha propuesto que el estado sub-óptimo de vitamina B6 se asocia con tamin B6 status could increase the risk for these chronic diseases. ciertas enfermedades que afligen en especial a la pobla- ción anciana: función cognitiva alterada, enfermedad de (Nutr Hosp. 2007;22:7-24) Alzheimer, cardiopatía y distintos tipos de cáncer. Algu- Key words: Vitamin B . Coenzyme. Elderly. Homocystei- nos de estos problemas podrían relacionarse con concen- 6 traciones elevadas de homocisteína asociadas con una ne. Vitamin B6 deficiency. deficiencia de vitamina B6, pero también existe la eviden- cia de otros mecanismos independientes de la homociste- ína por los que un estado sub-óptimo de vitamina B6 po- Correspondence: Prof. Dr. Marcela González-Gross dría aumentar el riesgo de padecer estas enfermedades Facultad de CC de la Actividad Física y del Deporte crónicas. Universidad Politécnica de Madrid Martín Fierro, s/n 28040 Madrid (Nutr Hosp. 2007;22:7-24) E-mail: [email protected] Palabras clave: Vitamina B6. Coenzima. Anciano. Homocis- Recibido: 15-XI-2006. teína. Deficiencia de vitamina B6. Aceptado: 10-XII-2006. 7 03. VITAMIN B6 10/1/07 07:45 Página 8 Introduction and pyridoxamin-5´-phosphate (PMP) are the biologi- cal active coenzyme forms (fig. 1). They are water-so- Vitamin B6 sufficiency is required for optimal he- luble and can be inter-converted in normal human me- alth. This is due to the participation in many different tabolism1. PLP is the major form that is used by biochemical reactions. Vitamin B6 and its derivatives pyridoxine-dependent enzymes. These enzymes ca- are needed, especially in there coenzyme functions, talyse more than 100 essential biochemical reactions for the main metabolic pathways in the human body. in human metabolism. For that reason, it is clear that a vitamin B6 deficiency, B6 vitamers are similarly absorbed in the upper je- even in mild forms, has effects on the human metabo- junum and little in ileum, but before absorption, lism. Several diseases and impairments of health are phosphate esters must be hydrolysed by alkaline connected to the wide variety of B6 functions in su- phosphatase or other intestinal phosphatases. The boptimal status. This can also be worsened through non-phosphorylated form enters the mucosal cells by ageing. two different processes according to luminal concen- This article gets deep into metabolic functions of tration. At low concentrations, vitamers enter the cell vitamin B6 and gives an overview about associated di- by an active process regulated by requirements. At seases to vitamin B6 deficiency with new insights high concentrations, transport is by non-saturable pas- from recently published studies, including prevention sive diffusion mechanisms1. Once in the cell, vitamers and treatment potentials. are phosphorylated by ATP dependent pyridoxine ki- nase in a process referred to as metabolic trapping. The phosphorylated form can not traverse cell mem- Vitamin B6 – Chemistry, metabolism and branes and must therefore be dephosphorylated again bioavailability before traversing the basolateral membrane side of the mucosal cell. Once in the circulation, most of B6 vita- Vitamin B6 comprises a group of three related 3-hy- mers are transported to the liver where they are again droxy-2-methyl-pyrimidine derivatives. The derivati- phosphorylated to PNP, PLP or PMP, and then relea- 1,2 ve pyridoxine (PN) is an alcohol, pyridoxal (PL) is an sed to plasma . Vitamin B6 in plasma is mainly PLP aldehyde and pyridoxamine (PM) contains an amino (60%), PN (15%) and PL (14%). These vitamers cir- group. Their respective 5´-phosphate esters: pyridoxi- culate bound to albumin1. In peripheral tissues, in or- ne 5´-phosphate (PNP), pyridoxal 5´-phosphate (PLP) der to cross cell membranes, the phosphorylated Fig. 1.—Metabolic inter- conversion of pyridoxine, pyridoxal, pyridoxamine and their respective phosp- hate esters (modified after Bässler, 2002). 8 Nutr Hosp. 2007;22(1):7-24 A. Spinneker y cols. 03. VITAMIN B6 10/1/07 07:45 Página 9 forms need to be dephosphorylated by alkaline phosp- enables the amino acid for further reactions. Some of horylase. Transport into tissue cells is by gradient dif- the reactions PLP is involved in are: transamination of fusion. This gradient is maintained thanks to the im- amino acids to keto acids (which can be then used for mediate rephosphorylation occurring inside the cells. gluconeogenesis), formation of α-aminolevuline acid Intracellular accumulation of PLP seems to be limited (a precursor of heme group), as coenzyme in serin- by intracellular protein binding capacity. In circula- palmityl-transferase (implicated in sphingomyelin tion, PLP may enter red blood cells where PLP synthesis), decarboxylation of L-amino acids (to yield bounds to haemoglobin. In red cell mass, PLP is at amines, which function as neurotransmitters, hormo- higher concentration (4 to 5 times) than in plasma. nes or biogenic amines). In the nervous system, PN- PLP increases the oxygen affinity of haemoglobin3. dependent enzymes fall into two categories: transami- Total body stores of B6 have been estimated to be as nases and L-amino acid decarboxylases. The crucial little as 167 mg4. Up to 80% of that amount is found in PLP-dependent steps of the synthesis of several neu- muscle tissue2. PLP in metabolism occurs mainly in rotransmitters are: the enzymatic decarboxylation of the liver where it is oxidized to 4-pyridoxic-acid (4- 3,4-dihydroxyphenylalanine (DOPA) to dopamine, PA) which is released and excreted. Almost 50% of the conversion of tryptophan to both nitric acid and α urinary vitamin B6 is 4-PA. In total, some 2 mg vita- serotonine, and the conversion of glutamic acid to - 10 min B6 can be excreted every day. In cases of B6 defi- aminobutyric-acid (GABA) . Another important me- ciency, excretion appears to be lower. PN is also ex- tabolic pathway is the metabolism of one-carbon creted in faeces but to a limited extent and can units. One-carbon (methyl) units, usually obtained therefore be neglected4. from serine, are transferred to tetrahydrofolate (THF) Gregory has reviewed the bioavailability of vitamin yielding 5,10-methylene-tetrahydrofolate (5,10- 5 B6 . In a diet typically containing about 15% PN glu- methylene-THF). This reaction is catalysed by serine- coside, which is about 50% as bioavailable as the ot- hydroxymethyltransferase (SHMT), a PLP dependent her vitamers, vitamin B6 is about 75% bioavailable.
Load more

Recommended publications
  • Guidelines on Food Fortification with Micronutrients
    GUIDELINES ON FOOD FORTIFICATION FORTIFICATION FOOD ON GUIDELINES Interest in micronutrient malnutrition has increased greatly over the last few MICRONUTRIENTS WITH years. One of the main reasons is the realization that micronutrient malnutrition contributes substantially to the global burden of disease. Furthermore, although micronutrient malnutrition is more frequent and severe in the developing world and among disadvantaged populations, it also represents a public health problem in some industrialized countries. Measures to correct micronutrient deficiencies aim at ensuring consumption of a balanced diet that is adequate in every nutrient. Unfortunately, this is far from being achieved everywhere since it requires universal access to adequate food and appropriate dietary habits. Food fortification has the dual advantage of being able to deliver nutrients to large segments of the population without requiring radical changes in food consumption patterns. Drawing on several recent high quality publications and programme experience on the subject, information on food fortification has been critically analysed and then translated into scientifically sound guidelines for application in the field. The main purpose of these guidelines is to assist countries in the design and implementation of appropriate food fortification programmes. They are intended to be a resource for governments and agencies that are currently implementing or considering food fortification, and a source of information for scientists, technologists and the food industry. The guidelines are written from a nutrition and public health perspective, to provide practical guidance on how food fortification should be implemented, monitored and evaluated. They are primarily intended for nutrition-related public health programme managers, but should also be useful to all those working to control micronutrient malnutrition, including the food industry.
    [Show full text]
  • VITAMIN DEFICIENCIES in RELATION to the EYE* by MEKKI EL SHEIKH Sudan VITAMINS Are Essential Constituents Present in Minute Amounts in Natural Foods
    Br J Ophthalmol: first published as 10.1136/bjo.44.7.406 on 1 July 1960. Downloaded from Brit. J. Ophthal. (1960) 44, 406. VITAMIN DEFICIENCIES IN RELATION TO THE EYE* BY MEKKI EL SHEIKH Sudan VITAMINS are essential constituents present in minute amounts in natural foods. If these constituents are removed or deficient such foods are unable to support nutrition and symptoms of deficiency or actual disease develop. Although vitamins are unconnected with energy and protein supplies, yet they are necessary for complete normal metabolism. They are, however, not invariably present in the diet under all circumstances. Childhood and periods of growth, heavy work, childbirth, and lactation all demand the supply of more vitamins, and under these conditions signs of deficiency may be present, although the average intake is not altered. The criteria for the fairly accurate diagnosis of vitamin deficiencies are evidence of deficiency, presence of signs and symptoms, and improvement on supplying the deficient vitamin. It is easy to discover signs and symptoms of vitamin deficiencies, but it is not easy to tell that this or that vitamin is actually deficient in the diet of a certain individual, unless one is able to assess the exact daily intake of food, a process which is neither simple nor practical. Another way of approach is the assessment of the vitamin content in the blood or the measurement of the course of dark adaptation which demon- strates a real deficiency of vitamin A (Adler, 1953). Both tests entail more or less tedious laboratory work which is not easy in a provincial hospital.
    [Show full text]
  • Vitamin B12 and Methylmalonic Acid Testing AHS – G2014
    Corporate Medical Policy Vitamin B12 and Methylmalonic Acid Testing AHS – G2014 File Name: vitamin_b12_and_methylmalonic_acid_testing Origination: 1/1/2019 Last CAP Review: 02/2021 Next CAP Review: 02/2022 Last Review: 02/2021 Description of Procedure or Service Vitamin B12, also known as cobalamin, is a water-soluble vitamin required for proper red blood cell formation, key metabolic processes, neurological function, and DNA regulation and synthesis. Hematologic and neuropsychiatric disorders caused by a deficiency in B12 can often be reversed by early diagnosis and prompt treatment (Oh & Brown, 2003). Methylmalonic acid is produced from excess methylmalonyl-CoA that accumulates when Vitamin B12 is unavailable and is considered an indicator of functional B12 deficiency (Sobczynska- Malefora et al., 2014). Holotranscobalamin (holoTC) is the metabolically active fraction of B12 and is an emerging marker of impaired vitamin B12 status (Langan & Goodbred, 2017). ***Note: This Medical Policy is complex and technical. For questions concerning the technical language and/or specific clinical indications for its use, please consult your physician. Policy BCBSNC will provide coverage for Vitamin B12 and Methylmalonic Acid Testing when it is determined the medical criteria or reimbursement guidelines below are met Benefits Application This medical policy relates only to the services or supplies described herein. Please refer to the Member's Benefit Booklet for availability of benefits. Member's benefits may vary according to benefit design; therefore member benefit language should be reviewed before applying the terms of this medical policy. When Vitamin B12 and Methylmalonic Acid Testing is covered 1. Reimbursement for vitamin B12 testing is allowed in individuals being evaluated for clinical manifestations of Vitamin B12 deficiency including: A.
    [Show full text]
  • Human Vitamin and Mineral Requirements
    Human Vitamin and Mineral Requirements Report of a joint FAO/WHO expert consultation Bangkok, Thailand Food and Agriculture Organization of the United Nations World Health Organization Food and Nutrition Division FAO Rome The designations employed and the presentation of material in this information product do not imply the expression of any opinion whatsoever on the part of the Food and Agriculture Organization of the United Nations concerning the legal status of any country, territory, city or area or of its authorities, or concern- ing the delimitation of its frontiers or boundaries. All rights reserved. Reproduction and dissemination of material in this information product for educational or other non-commercial purposes are authorized without any prior written permission from the copyright holders provided the source is fully acknowledged. Reproduction of material in this information product for resale or other commercial purposes is prohibited without written permission of the copyright holders. Applications for such permission should be addressed to the Chief, Publishing and Multimedia Service, Information Division, FAO, Viale delle Terme di Caracalla, 00100 Rome, Italy or by e-mail to [email protected] © FAO 2001 FAO/WHO expert consultation on human vitamin and mineral requirements iii Foreword he report of this joint FAO/WHO expert consultation on human vitamin and mineral requirements has been long in coming. The consultation was held in Bangkok in TSeptember 1998, and much of the delay in the publication of the report has been due to controversy related to final agreement about the recommendations for some of the micronutrients. A priori one would not anticipate that an evidence based process and a topic such as this is likely to be controversial.
    [Show full text]
  • Folate and Vitamin B12: Function and Importance in Cognitive Development Aron M
    Folate, Vitamin B12 and Brain Bhutta ZA, Hurrell RF, Rosenberg IH (eds): Meeting Micronutrient Requirements for Health and Development. Nestlé Nutr Inst Workshop Ser, vol 70, pp 161–171, Nestec Ltd., Vevey/S. Karger AG., Basel, © 2012 Folate and Vitamin B12: Function and Importance in Cognitive Development Aron M. Troen Nutrition and Brain Health Laboratory, Institute of Biochemistry, Food Science and Nutrition, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel Abstract The importance of the B vitamins folate and vitamin B12 for healthy neurological develop- ment and function is unquestioned. Folate and vitamin B12 are required for biological methylation and DNA synthesis. Vitamin B12 also participates in the mitochondrial catabo- lism of odd-chain fatty acids and some amino acids. Inborn errors of their metabolism and severe nutritional deficiencies cause serious neurological and hematological pathology. Poor folate and vitamin B12 status short of clinical deficiency is associated with increased risk of cognitive impairment, depression, Alzheimer’s disease and stroke among older adults and increased risk of neural tube defects among children born to mothers with low folate status. Folate supplementation and food fortification are known to reduce incident neural tube defects, and B vitamin supplementation may have cognitive benefit in older adults. Less is known about folate and vitamin B12 requirements for optimal brain devel- opment and long-term cognitive health in newborns, children and adolescents. While increasing suboptimal nutritional status has observed benefits, the long-term effects of high folate intake are uncertain. Several observations of unfavorable health indicators in children and adults exposed to high folic acid intake make it imperative to achieve a more precise definition of folate and B12 requirements for brain development and function.
    [Show full text]
  • 243 Public Health Reviews, Vol
    243 Public Health Reviews, Vol. 32, No 1, 243-255 Micronutrient Defi ciency Conditions: Global Health Issues Theodore H Tulchinsky, MD, MPH1 ABSTRACT Micronutrient defi ciency conditions are widespread among 2 billion people in developing and in developed countries. These are silent epidemics of vitamin and mineral defi ciencies affecting people of all genders and ages, as well as certain risk groups. They not only cause specifi c diseases, but they act as exacerbating factors in infectious and chronic diseases, greatly impacting morbidity, mortality, and quality of life. Defi ciencies in some groups of people at special risk require supplementation, but the most effective way to meet community health needs safely is by population based approaches involving food fortifi cation. These complementary methods, along with food security, education, and monitoring, are challenges for public health and for clinical medicine. Micronutrient defi ciency conditions relate to many chronic diseases, such as osteoporosis osteomalacia, thyroid defi ciency colorectal cancer and cardiovascular diseases. Fortifi cation has a nearly century long record of success and safety, proven effective for prevention of specifi c diseases, including birth defects. They increase the severity of infectious diseases, such as measles, HIV/AIDS and tuberculosis. Understanding the pathophysiology and epidemiology of micronutrient defi ciencies, and implementing successful methods of prevention, both play a key part in the New Public Health as discussed in this section, citing the examples of folic acid, vitamin B12, and vitamin D. Key Words: micronutrient defi ciency conditions, global health, folic acid, vitamin D, vitamin B12, defi ciency INTRODUCTION Micronutrient Defi ciencies (MNDs) are of great public health and socio- economic importance worldwide.
    [Show full text]
  • Vitamin Excess and Deficiency Liliane Diab and Nancy F
    Vitamin Excess and Deficiency Liliane Diab, MD,* Nancy F. Krebs, MD, MS* *Section of Nutrition, Department of Pediatrics, University of Colorado School of Medicine and Children’s Hospital Colorado, Aurora, CO Education Gap Vitamins are organic compounds that humans cannot synthesize but need in small amounts to sustain life. Pediatricians’ knowledge about vitamins is challenged daily. Pediatricians are faced not only with parents requesting supplements but also with parents refusing them when they are clinically indicated. In addition, pediatricians need to be familiar with the effect of maternal health and diet on human milk to counsel their patients on how to prevent potentially devastating health consequences for the breastfed infant. Tables 1 and 2 provide the reader with a quick reference to who is at risk and when to consider a vitamin or mineral deficiency (minerals will be covered in the second part of this review). Table 3 summarizes the pharmaceutical and AUTHOR DISCLOSURE Drs Diab and Krebs supplemental sources of vitamin D and Table 4 provides a quick reference for have disclosed no financial relationships diagnostic tests and treatment doses for vitamin deficiencies. relevant to this article. This commentary does not contain a discussion of an unapproved/ investigative use of a commercial product/ device. Objectives After completing this article, readers should be able to: ABBREVIATIONS 1. Discuss the risk factors for developing selected vitamin deficiencies. AAP American Academy of Pediatrics 2. Identify the role of natural foods, fortified foods, and supplements in CT computed tomography meeting the Dietary Reference Intakes of various vitamins. DRIs Dietary Reference Intakes FDA Food and Drug Administration 3.
    [Show full text]
  • An Update of Vitamin B12 Metabolism and Deficiency States Randall Swain, MD [Charleston, West Virginia
    Clinical Review An Update of Vitamin B12 Metabolism and Deficiency States Randall Swain, MD [Charleston, West Virginia, Vitamin B12 deficiency may be underestimated in the shortcomings of the various tests. Current state-of-the- reneral population. High-risk groups for the deficiency art testing uses serum cobalamin levels as a screening {syndrome include the elderly, patients taking ulcer med­ test and serum or urine homocysteine and methylma­ ications over long periods, patients with acquired immu­ lonic acid determinations as confirmatory tests. Vitamin nodeficiency syndrome, vegetarians, patients who have B12 deficiency is treatable with monthly injections, large |undergone stomach resection or small bowel resection, doses of daily oral supplement tablets, or an intranasal or both, and patients with dementia. gel, which is far better absorbed than comparable oral The vitamin B12 deficiency syndrome is characterized by supplements. five stages, the fifth of which results in irreversible neu­ ropsychiatric manifestations. Although the deficiency is Key words. Vitamin deficiency; vitamin B12. easily treated, diagnosis is somewhat complicated by the ( / Fam Pract 1995; 41:595-600) Since the discovery of vitamin B12 in 1948, physicians transported from the proximal ileum to the distal ileum, have been aware, at least to some extent, of its importance where it is then bound to transcobalamin II for transport to the human body. Today, as medical research focuses to the liver and bone marrow. increasingly on vitamins, the importance of B12 is becom­ The recommended daily allowance (RDA) of vita­ ing even clearer. This review includes information on vi­ min B , 2 is 2 ij,g /d in the average adult, and the average tamin B12 deficiency, changing options in laboratory' test­ daily intake is between 6 and 7 jug/d.1 The body stores 2 ing for deficiency states, and both old and new options for to 5 mg of the vitamin, 50% of which is stored in the liver.2 treatment.
    [Show full text]
  • Vitamin B12 Deficiency Some Observations, Some Misconceptions
    Eur J Gen Med 2015; 12(3):261 -266 Case Report DOI : 10.15197/ ejgm.01427 Vitamin B12 Deficiency Some Observations, Some Misconceptions Rehman HU ABSTRACT Functional vitamin B12 deficiency is a syndrome where a wide variety of symptoms in the presence of “normal” serum levels of the vitamin respond to vitamin B12 therapy. A series of patients with functional vitamin B12 deficiency are described whose presenting features were drenching night sweats and fatigue. Reliance on serum vitamin B12 levels as a diagnostic test would have obscured the cause of their symptoms. Serum homocysteine and/or methlymalonic acid levels should be done in all patients with suspected B12 deficiency. Normal levels of these metabolites do not exclude diagnosis and empirical treatment may be justifiable in certain cases. Author also argues that oral vitamin B12 treatment results in suboptimal clinical response in a vast majority of patients and intramuscular route should be preferred in most patients. Key words: Vitamin B12, night sweats, homocysteine, mathylmalonic acid, autonomic dysfunction B12 Vitamini Eksikliği Bazı Gözlemler, Bazı Yanılgılar ÖZET Fonksiyonel vitamin B12 eksikliği B12 tedaviye yanıtta vitaminin normal serum seviyelerinin mevcudiyetinde semptomlarının çok çeşitli olduğu bir sendromdur. Fonksiyonel B12 vitamini eksikliği olan bir dizi hastaların olan başvuru özellikleri gece terlemeleri ve yorgunluk derceleri burada açıklanmıştır. Bir tanı testi olarak serum vitamin B12 düzeylerine güven belirtilerin nedenini gizle- mektedir. Serum homosistein ve/veya methlymalonic asit düzeyleri şüpheli B12 eksikliği olan tüm hastalarda yapılmalıdır. Bu me- tabolitlerin normal düzeyleri tanıyı dışlamaz ve ampirik tedavi bazı olgularda gerekli olabilir. Yazar hastaların çoğunluğunda vita- min B12 tedavisinin suboptimal klinik cevap ile sonuçlanabileceğini çoğu hastada intramuskuler yolun tercih edilmesi gerektiğini savunuyor.
    [Show full text]
  • The Vitamin a Story Lifting the Shadow of Death the Vitamin a Story – Lifting the Shadow of Death World Review of Nutrition and Dietetics
    World Review of Nutrition and Dietetics Editor: B. Koletzko Vol. 104 R.D. Semba The Vitamin A Story Lifting the Shadow of Death The Vitamin A Story – Lifting the Shadow of Death World Review of Nutrition and Dietetics Vol. 104 Series Editor Berthold Koletzko Dr. von Hauner Children’s Hospital, Ludwig-Maximilians University of Munich, Munich, Germany Richard D. Semba The Vitamin A Story Lifting the Shadow of Death 41 figures, 2 in color and 9 tables, 2012 Basel · Freiburg · Paris · London · New York · New Delhi · Bangkok · Beijing · Tokyo · Kuala Lumpur · Singapore · Sydney Dr. Richard D. Semba The Johns Hopkins University School of Medicine Baltimore, Md., USA Library of Congress Cataloging-in-Publication Data Semba, Richard D. The vitamin A story : lifting the shadow of death / Richard D. Semba. p. ; cm. -- (World review of nutrition and dietetics, ISSN 0084-2230 ; v. 104) Includes bibliographical references and index. ISBN 978-3-318-02188-2 (hard cover : alk. paper) -- ISBN 978-3-318-02189-9 (e-ISBN) I. Title. II. Series: World review of nutrition and dietetics ; v. 104. 0084-2230 [DNLM: 1. Vitamin A Deficiency--history. 2. History, 19th Century. 3. Night Blindness--history. 4. Vitamin A--therapeutic use. W1 WO898 v.104 2012 / WD 110] 613.2'86--dc23 2012022410 Bibliographic Indices. This publication is listed in bibliographic services, including Current Contents® and PubMed/MEDLINE. Disclaimer. The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publisher and the editor(s). The appearance of advertisements in the book is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety.
    [Show full text]
  • Prevalence and Predictors of Vitamin D Deficiency and Insufficiency
    nutrients Article Prevalence and Predictors of Vitamin D Deficiency and Insufficiency among Pregnant Rural Women in Bangladesh Faruk Ahmed 1,*, Hossein Khosravi-Boroujeni 1, Moududur Rahman Khan 2, Anjan Kumar Roy 3 and Rubhana Raqib 3 1 Public Health, School of Medicine, Griffith University, Gold Coast Campus, Gold Coast, QLD 4220, Australia; [email protected] 2 Institute of Nutrition and Food Science, University of Dhaka, Dhaka 1000, Bangladesh; [email protected] 3 International Centre for Diarrhoeal Disease Research, Mohakhali, Dhaka 1212, Bangladesh; [email protected] (A.K.R.); [email protected] (R.R.) * Correspondence: f.ahmed@griffith.edu.au Abstract: Although adequate vitamin D status during pregnancy is essential for maternal health and to prevent adverse pregnancy outcomes, limited data exist on vitamin D status and associated risk factors in pregnant rural Bangladeshi women. This study determined the prevalence of vitamin D deficiency and insufficiency, and identified associated risk factors, among these women. A total of 515 pregnant women from rural Bangladesh, gestational age ≤ 20 weeks, participated in this cross-sectional study. A separate logistic regression analysis was applied to determine the risk factors of vitamin D deficiency and insufficiency. Overall, 17.3% of the pregnant women had vitamin D deficiency [serum 25(OH)D concentration <30.0 nmol/L], and 47.2% had vitamin D insufficiency [serum 25(OH)D concentration between 30–<50 nmol/L]. The risk of vitamin D insufficiency was significantly higher among nulliparous pregnant women (OR: 2.72; 95% CI: 1.75–4.23), those in their first trimester (OR: Citation: Ahmed, F.; 2.68; 95% CI: 1.39–5.19), anaemic women (OR: 1.53; 95% CI: 0.99–2.35; p = 0.056) and women whose Khosravi-Boroujeni, H.; Khan, M.R.; Roy, A.K.; Raqib, R.
    [Show full text]
  • Iodine Consumption and Hashimoto's Thyroiditis: a Systematic Literature
    THESIS CALIFORNIASTATE UNIVERSITY SAN MARCOS THESIS SUBMITTED IN PARTIAL FULFILLMENTOF THE REQUIREMENTSFOR THE DEGREE :tv1ASTER OF PUBLIC HEAL TH TITLE: Hashimoto's Thyroiditis and Iodine Consumption AUTHOR(S): Sandra Cracchiolo DATE OF SUCCESSFUL DEFENSE: 04/23/2020 THE THESIS HAS BEEN ACCEPTED BY THE THESIS COMMITTEE IN PARTIAL FULFILLMENTOF THE REQUIREMENTS FOR THE DEGREE OF :tv1ASTER OF PUBLIC HEAL TH Asherlev Santos May 4, 2020 COMMITTEECHAIR SIGNATURE DATE Kathryn Hollenbach May 4, 2020 COMMITTEE MEMBER SIGNATURE DATE COMMITTEE MEMBER SIGNATURE DATE COMMITTEE MEMBER SIGNATURE DATE Iodine Consumption and Hashimoto’s Thyroiditis: A Systematic Literature Review Sandra Cracchiolo California State University San Marcos IODINE AND HASHIMOTO’S THYROIDITIS 2 Abstract Iodine deficiency is a global health problem that is affecting over 2 billion people worldwide and 50 million people are dealing with the health issues directly related to being iodine deficient. The Universal Salt Iodization policy was created as a global initiative to eliminate iodine deficiency disorders worldwide and was implemented on a mandatory or voluntary basis. Hashimoto’s thyroiditis is an autoimmune disease that attacks healthy thyroid cells by an antibody-mediated immune response. This disease affects 1.5 per 1000 worldwide and that number is continuing to increase. This systematic literature review examined previous studies to determine if an association exists between the prevalence of Hashimoto’s thyroiditis in relation to the levels of iodine consumption after universal salt iodization. Keywords: Iodine, autoimmune thyroiditis, autoimmune disease, antibodies, Hashimoto’s thyroiditis, Universal Salt Iodization policy IODINE AND HASHIMOTO’S THYROIDITIS 3 Acknowledgements I would like to thank my committee for their continuous support throughout the development of my thesis.
    [Show full text]