DOCSLIB.ORG

Immunomodulatory Effects of Vitamin D in Thyroid Diseases

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Immunomodulatory Effects of Vitamin D in Thyroid Diseases nutrients Review Immunomodulatory Effects of Vitamin D in Thyroid Diseases Chiara Mele 1,2, Marina Caputo 3,4, Alessandro Bisceglia 5, Maria Teresa Samà 4, Marco Zavattaro 4,5, Gianluca Aimaretti 1,4, Loredana Pagano 5, Flavia Prodam 3,4 and Paolo Marzullo 1,2,* 1 Department of Translational Medicine, University of Piemonte Orientale UPO, 28100 Novara, Italy; [email protected] (C.M.); [email protected] (G.A.) 2 Division of General Medicine, S. Giuseppe Hospital, I.R.C.C.S. Istituto Auxologico Italiano, 28824 Verbania, Italy 3 Department of Health Sciences, University of Piemonte Orientale UPO, 28100 Novara, Italy; [email protected] (M.C.); fl[email protected] (F.P.) 4 Division of Endocrinology, University Hospital “Maggiore della Carità”, 28100 Novara, Italy; [email protected] (M.T.S.); [email protected] (M.Z.) 5 Division of Endocrinology, Diabetology and Metabolism, Department of Medical Sciences, University of Turin, 10126 Turin, Italy; [email protected] (A.B.); [email protected] (L.P.) * Correspondence: [email protected]; Tel.: +39-03-2351-4436 Received: 19 April 2020; Accepted: 14 May 2020; Published: 16 May 2020 Abstract: Vitamin D is a secosteroid with a pleiotropic role in multiple physiological processes. Besides the well-known activity on bone homeostasis, recent studies suggested a peculiar role of vitamin D in different non-skeletal pathways, including a key role in the modulation of immune responses. Recent evidences demonstrated that vitamin D acts on innate and adaptative immunity and seems to exert an immunomodulating action on autoimmune diseases and cancers. Several studies demonstrated a relationship between vitamin D deficiency, autoimmune thyroid disorders, and thyroid cancer. This review aims to summarize the evidences on the immunomodulatory effect of vitamin D on thyroid diseases. Keywords: vitamin D; immune system; thyroid autoimmunity; thyroid cancer 1. Introduction Vitamin D is a secosteroidal hormone precursor. This term encompasses several compounds, but the most represented isoforms are Ergocalciferol (or vitamin D2), available in plants, and Cholecalciferol (or vitamin D3), synthesized at the skin level from 7-dehydrocholesterol after exposure to ultraviolet B (UVB) radiation [1,2]. Vitamin D binding protein transports vitamin D isoforms to the liver, where they are converted by 25-hydroxylase enzyme to 25-hydroxyvitamin D2 (25(OH)D2) and D3 (25(OH)D3), which are the main circulating isoforms of vitamin D and reflect vitamin D status [1,3]. Considering that D3 is the most represented isoform in humans [4], from now on we will conventionally use the terminology associated with this isoform. At physiological concentrations, 25(OH)D3 is inactive, needing to be converted into the active forms 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) by 1α-hydroxylase enzyme (encoded by CYP27B1) in the kidneys. 1α-hydroxylase activity is regulated by parathyroid hormone (PTH) levels, while high 1,25(OH)2D3 levels and fibroblast growth factor 23 (FGF23) exert a negative feedback. 1α-hydroxylase is also expressed in extra-renal sites, like bone, skin, colon, brain, and immune cells, where its regulation is independent of PTH. Inactivation of both 25(OH)D3 and 1,25(OH)2D3 is performed by 24-hydroxylase [1,2,5]. Nutrients 2020, 12, 1444; doi:10.3390/nu12051444 www.mdpi.com/journal/nutrients NutrientsNutrients 20202020,, 1212,, 1444x FOR PEER REVIEW 22 of 2019 1,25(OH)2D3 binds to the Vitamin D receptor (VDR), a member of the nuclear hormone receptors1,25(OH)2D3 family, bindsacting to on the the Vitamin vitamin D receptorD response (VDR), element a member (VDRE) of the to nuclearcontrol hormone the expression receptors of family,multiple acting genes, on including the vitamin those D response involved element in the (VDRE) regulation to control of cellular the expression cycle and ofangiogenesis multiple genes, [6]. includingMoreover, thosethe existence involved of ina membrane-bound the regulation of VD cellularR has cyclebeen hypothesized and angiogenesis mediating [6]. Moreover, non-genomic, the existencerapid effects of a of membrane-bound 1,25(OH)2D3 [7]. VDR has been hypothesized mediating non-genomic, rapid effects of 1,25(OH)2D31,25(OH)2D3 [7]. has been recognized as a key hormone in the regulation of the musculoskeletal homeostasis.1,25(OH)2D3 However, has been extra-skeletal recognized effects as a keyof 1,25(OH)2D3 hormone in have the regulation been attracting of the interest musculoskeletal in the last homeostasis.years, after discovering However, extra-skeletalthe presence eofff ectsVDR of in 1,25(OH)2D3 many tissue have types been [8,9]. attracting Thus, different interest roles in the have last years,been afterattributed discovering to vitamin the presence D: it contributes of VDR in many to the tissue development, types [8,9]. Thus,protection, different transmission, roles have beenand attributedplasticity of to the vitamin nervous D: itsystem, contributes downregulates to the development, the renin-angiotensin-aldosterone protection, transmission, system, and plasticity exerts a ofprotective the nervous role system, on the downregulatesvascular endothelium, the renin-angiotensin-aldosterone and improves insulin sensitivity system, exerts[10–13]. a protectiveFor these rolephysiological on the vascular evidences, endothelium, vitamin D and status improves has been insulin proposed sensitivity as a biomarker [10–13]. For of these general physiological health and evidences,hypovitaminosis vitamin D D statushas been has beencorrelated proposed to the as a biomarkerpresence of of generalmetabolic health syndrome, and hypovitaminosis cardiovascular D hasdiseases, been correlatedcancers, infections, to the presence neuromuscular of metabolic disorders, syndrome, and cardiovascular all-cause mortality diseases, [14–16]. cancers, infections, neuromuscularAmong the disorders, pleotropic and effects all-cause of vitamin mortality D, [14in –the16]. last few decades an increasing number of evidencesAmong suggested the pleotropic an intriguing effects of vitamin link between D, in the lastvitamin few decades D homeostasis an increasing and numberimmune of evidencesresponses suggested[17–19]. As an such, intriguing many researcher link betweens speculated vitamin D that homeostasis autoimmune and immunedisorders, responses including [17 type–19 ].I diabetes, As such, manyautoimmune researchers thyroiditis, speculated inflammatory that autoimmune bowel disorders, disease, includingrheumatoid type arthritis, I diabetes, systemic autoimmune lupus thyroiditis,erythematosus, inflammatory and multiple bowel sclerosis, disease, could rheumatoid be related arthritis, to vitamin systemic D lupusimbalance erythematosus, [20,21]. In andthis multiplecontext, sclerosis,vitamin D could could be exert related anto important vitamin D role imbalance in innate [20 ,and21]. adaptive In this context, immunity vitamin modulation D could exert(Figure an 1). important role in innate and adaptive immunity modulation (Figure1). FigureFigure 1.1. SchemeScheme ofof vitaminvitamin DD modulatingmodulating rolerole inin immuneimmune response.response. AsAs detaileddetailed inin thethe text,text, vitaminvitamin DD interferesinterferes withwith innateinnate andand adaptativeadaptative immunityimmunity throughthrough didifferentfferentmechanisms. mechanisms. ArrowsArrows illustrateillustrate increaseincrease ( (),↑), decrease decrease ( ) or(↓) regulationor regulation/modulation/modulation ( ) of ( specific↗) of specific actions, processes,actions, processes, cells, or molecules. cells, or " # % Abbreviations:molecules. Abbreviations: CAMP, cathelicidin CAMP, antimicrobial cathelicidin peptide;antimicrobial FasL, Fas-ligand;peptide; FasL, IL, Interleukin; Fas-ligand; NETs, IL, neutrophilInterleukin; extracellular NETs, neutrophil traps; TGF,extracellular transforming traps; growth TGF, transforming factor; Th, T helper;growth TNF, factor; Tumor Th, T Necrosis helper; Factor;TNF, Tumor Treg, TNecrosis regulatory. Factor; Treg, T regulatory. InnateInnate immunity immunity is anis immunologicalan immunological subsystem subsystem that includes that includes the cells andthe mechanismscells and mechanisms implicated inimplicated the first line in ofthe defense first line from of infections.defense from The infect vitaminions. D bindingThe vitamin to VDR D expressedbinding to by VDR the hematopoietic expressed by systemthe hematopoietic leads to the system myeloid leads diff erentiationto the myeloid towards differentiation monocytes towards and granulocytes, monocytes and the immunegranulocytes, cells involvedthe immune in the cells innate involved immunity. in the The innate exposure immuni of monocytesty. The exposure to different of pathogensmonocytesincreases to different the expressionpathogens ofincreases VDR, which the expression is involved of in antimicrobialVDR, which responseis involved [22 ].in Focusing antimicrobial on innate response immunity, [22]. 1,25(OH)2D3Focusing on enhancesinnate immunity, antimicrobial 1,25(OH)2D3 activity ofenhances monocytes antimicrobial and macrophages activity of by monocytes promoting and the productionmacrophages of by defensin promotingβ 2 andthe cathelicidinproduction of antimicrobial defensin β 2 peptide and cathelicidin (CAMP) [antimicrobial23,24]. Furthermore, peptide 1,25(OH)2D3(CAMP) [23,24]. contributes Furthermore, to the 1, clearance25(OH)2D3 of pathogens contributes by to inducing the clearance chemotaxis of pathogens
Load more

Recommended publications
  • Does Dietary Fiber Affect the Levels of Nutritional Components After Feed Formulation?
    fibers Article Does Dietary Fiber Affect the Levels of Nutritional Components after Feed Formulation? Seidu Adams 1 ID , Cornelius Tlotliso Sello 2, Gui-Xin Qin 1,3,4, Dongsheng Che 1,3,4,* and Rui Han 1,3,4 1 College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China; [email protected] (S.A.); [email protected] (G.-X.Q.); [email protected] (R.H.) 2 College of Animal Science and Technology, Department of Animal Genetics, Breeding and Reproduction, Jilin Agricultural University, Changchun 130118, China; [email protected] 3 Key Laboratory of Animal Production, Product Quality and Security, Jilin Agricultural University, Ministry of Education, Changchun 130118, China 4 Jilin Provincial Key Laboratory of Animal Nutrition and Feed Science, Jilin Agricultural University, Changchun 130118, China * Correspondence: [email protected]; Tel.: +86-136-4431-9554 Received: 12 January 2018; Accepted: 25 April 2018; Published: 7 May 2018 Abstract: Studies on dietary fiber and nutrient bioavailability have gained an increasing interest in both human and animal nutrition. Questions are increasingly being asked regarding the faith of nutrient components such as proteins, minerals, vitamins, and lipids after feed formulation. The aim of this review is to evaluate the evidence with the perspective of fiber usage in feed formulation. The consumption of dietary fiber may affect the absorption of nutrients in different ways. The physicochemical factors of dietary fiber, such as fermentation, bulking ability, binding ability, viscosity and gel formation, water-holding capacity and solubility affect nutrient absorption. The dietary fiber intake influences the different methods in which nutrients are absorbed.
    [Show full text]
  • Recent Insights Into the Role of Vitamin B12 and Vitamin D Upon Cardiovascular Mortality: a Systematic Review
    Acta Scientific Pharmaceutical Sciences (ISSN: 2581-5423) Volume 2 Issue 12 December 2018 Review Article Recent Insights into the Role of Vitamin B12 and Vitamin D upon Cardiovascular Mortality: A Systematic Review Raja Chakraverty1 and Pranabesh Chakraborty2* 1Assistant Professor, Bengal School of Technology (A College of Pharmacy), Sugandha, Hooghly, West Bengal, India 2Director (Academic), Bengal School of Technology (A College of Pharmacy),Sugandha, Hooghly, West Bengal, India *Corresponding Author: Pranabesh Chakraborty, Director (Academic), Bengal School of Technology (A College of Pharmacy), Sugandha, Hooghly, West Bengal, India. Received: October 17, 2018; Published: November 22, 2018 Abstract since the pathogenesis of several chronic diseases have been attributed to low concentrations of this vitamin. The present study Vitamin B12 and Vitamin D insufficiency has been observed worldwide at all stages of life. It is a major public health problem, throws light on the causal association of Vitamin B12 to cardiovascular disorders. Several evidences suggested that vitamin D has an effect in cardiovascular diseases thereby reducing the risk. It may happen in case of gene regulation and gene expression the vitamin D receptors in various cells helps in regulation of blood pressure (through renin-angiotensin system), and henceforth modulating the cell growth and proliferation which includes vascular smooth muscle cells and cardiomyocytes functioning. The present review article is based on identifying correct mechanisms and relationships between Vitamin D and such diseases that could be important in future understanding in patient and healthcare policies. There is some reported literature about the causative association between disease (CAD). Numerous retrospective and prospective studies have revealed a consistent, independent relationship of mild hyper- Vitamin B12 deficiency and homocysteinemia, or its role in the development of atherosclerosis and other groups of Coronary artery homocysteinemia with cardiovascular disease and all-cause mortality.
    [Show full text]
  • Download Leaflet View the Patient Leaflet in PDF Format
    Read all of this leaflet carefully before you are given this within the body usually caused by diseases of the gut, liver any other medicines. Driving and using machines medicine because it contains important information for or gall bladder. • Medicines for heart disease such as digoxin or verapamil as Ergocalciferol may cause drowsiness or your eyes to you. It is important that you have this medicine so that your these can cause high levels of calcium in the blood leading become very sensitive to light. If this happens to you, do bones and teeth form properly. • Keep this leaflet. You may need to read it again. to an irregular or fast heart beat. not drive or use machinery. • If you have any further questions, ask your doctor or nurse. 2. What you need to know before you are given • Antacids containing magnesium for indigestion. If you are 3. How you will be given Ergocalciferol • If you get any side effects, talk to your doctor or nurse. Ergocalciferol on kidney dialysis this can lead to high levels of Ergocalciferol will be given to you by your doctor or nurse. This includes any possible side effects not listed in this magnesium in the blood which causes muscle weakness, Important: Your doctor will choose the dose that is right leaflet. See section 4. You must not be given Ergocalciferol: low blood pressure, depression and coma. for you. In this leaflet, Ergocalciferol 300,000 IU Injection BP will • if you are allergic to ergocalciferol (vitamin D) or any of the other • Thiazide diuretics (‘water tablets’) to relieve water You will be given Ergocalciferol by your doctor or nurse as an injection into a muscle.
    [Show full text]
  • 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 B12 Vitamin D Iodine and Selenium
    Frequently Asked Questions for VEG 1 General 1. Why has VEG 1 been developed? VEG 1 was developed to provide a convenient way of avoiding the most common weak points in a varied vegan diet: vitamin B12, iodine, vitamin D and selenium. Vitamin B12 Vitamin B12 is almost entirely absent from modern plant foods which are not contaminated by bacteria and insects. Even unwashed, organically grown plants do not contain a significant amount of B12. Vegans often have intakes of vitamin B12 well below recommended intakes. Low vitamin B12 intake by vegans routinely leads to reduced activity of some important enzymes and increased levels of homocysteine and methylmalonic acid (MMA). Even moderately elevated homocysteine is associated with increased risk of death, depression, stroke, dementia and birth defects, though it remains unclear how many of these associations reflect true cause and effect. Vegans who do not get vitamin B12 from fortified food or supplements are at increased risk of clinical deficiency symptoms such as anaemia and nervous system damage. The most common early symptoms of vitamin B12 deficiency are tiredness (from anaemia), numbness and tingling (from nervous system damage) and sore tongue. VEG 1 is designed to provide sufficient absorbed vitamin B12 to match national and international recommended intakes. It is designed to be chewed as this increases the reliability of vitamin B12 absorption by dispersing and dissolving the tablet. Vitamin D In the winter – whenever our shadows at midday are more than twice as long as we are – our skin cannot produce vitamin D effectively and even small dietary intakes may become important to avoid deficiency.
    [Show full text]
  • Analysis of Phenolic and Cyclic Compounds in Plants Using Derivatization Techniques in Combination with GC-MS-Based Metabolite Profiling
    Molecules 2015, 20, 3431-3462; doi:10.3390/molecules20023431 OPEN ACCESS molecules ISSN 1420-3049 www.mdpi.com/journal/molecules Review Analysis of Phenolic and Cyclic Compounds in Plants Using Derivatization Techniques in Combination with GC-MS-Based Metabolite Profiling Jens Rohloff Department of Biology, Norwegian University of Science and Technology, Trondheim 7491, Norway; E-Mail: [email protected]; Tel.: +47-7359-6093; Fax: +47-7359-6100 Academic Editor: Derek J. McPhee Received: 18 December 2014 / Accepted: 10 February 2015 / Published: 17 February 2015 Abstract: Metabolite profiling has been established as a modern technology platform for the description of complex chemical matrices and compound identification in biological samples. Gas chromatography coupled with mass spectrometry (GC-MS) in particular is a fast and accurate method widely applied in diagnostics, functional genomics and for screening purposes. Following solvent extraction and derivatization, hundreds of metabolites from different chemical groups can be characterized in one analytical run. Besides sugars, acids, and polyols, diverse phenolic and other cyclic metabolites can be efficiently detected by metabolite profiling. The review describes own results from plant research to exemplify the applicability of GC-MS profiling and concurrent detection and identification of phenolics and other cyclic structures. Keywords: derivatization; food chemistry; gas chromatography; mass spectrometry; phenols; phenolic acids 1. Introduction Chromatographic techniques for the detection and identification of metabolites in plant material have undergone major changes in recent years due to improvements of analysis time, detection limit and separation characteristics. Depending on the biological question, one might distinguish between targeted and non-targeted strategies. Gas chromatography (GC) in particular is characterized by sensitivity and reliability of separations and detection of complex sample mixtures.
    [Show full text]
  • Effects of Vitamin D Deficiency on the Improvement of Metabolic Disorders
    www.nature.com/scientificreports OPEN Efects of vitamin D defciency on the improvement of metabolic disorders in obese mice after vertical sleeve gastrectomy Jie Zhang1,2,7, Min Feng3,7, Lisha Pan4,7, Feng Wang1,3, Pengfei Wu4, Yang You4, Meiyun Hua4, Tianci Zhang4, Zheng Wang5, Liang Zong6*, Yuanping Han4* & Wenxian Guan1,3* Vertical sleeve gastrectomy (VSG) is one of the most commonly performed clinical bariatric surgeries for the remission of obesity and diabetes. Its efects include weight loss, improved insulin resistance, and the improvement of hepatic steatosis. Epidemiologic studies demonstrated that vitamin D defciency (VDD) is associated with many diseases, including obesity. To explore the role of vitamin D in metabolic disorders for patients with obesity after VSG. We established a murine model of diet- induced obesity + VDD, and we performed VSGs to investigate VDD’s efects on the improvement of metabolic disorders present in post-VSG obese mice. We observed that in HFD mice, the concentration of VitD3 is four fold of HFD + VDD one. In the post-VSG obese mice, VDD attenuated the improvements of hepatic steatosis, insulin resistance, intestinal infammation and permeability, the maintenance of weight loss, the reduction of fat loss, and the restoration of intestinal fora that were weakened. Our results suggest that in post-VSG obese mice, maintaining a normal level of vitamin D plays an important role in maintaining the improvement of metabolic disorders. Obesity and its related comorbidities afect 2.1 billion people worldwide1. In last decade, bariatric surgery has emerged as an efective treatment for obese individuals because of its sustained ability to reduce body weight 2–4.
    [Show full text]
  • These Highlights Do Not Include All the Information Needed to Use M.V.I. Pediatric® Safely and Effectively
    M.V.I. PEDIATRIC- ascorbic acid, retinol, ergocalciferol, thiamine hydrochloride, riboflavin 5- phosphate sodium, pyridoxine hydrochloride, niacinamide, dexpanthenol, .alpha.-tocopherol acetate, dl-, biotin, folic acid, cyanocobalamin, and phytonadione injection, powder, lyophilized, for solution Hospira, Inc. ---------- HIGHLIGHTS OF PRESCRIBING INFORMATION These highlights do not include all the information needed to use M.V.I. Pediatric® safely and effectively. See full prescribing information for M.V.I. Pediatric. M.V.I. Pediatric (multiple vitamins for injection), for intravenous use Initial U.S. Approval: 1983 RECENT MAJOR CHANGES Dosage And Administration, Dosage Information (2.2) 2/2019 INDICATIONS AND USAGE M.V.I. Pediatric is a combination of vitamins indicated for the prevention of vitamin deficiency in pediatric patients up to 11 years of age receiving parenteral nutrition (1) DOSAGE AND ADMINISTRATION M.V.I. Pediatric is a combination product that contains the following vitamins: ascorbic acid, vitamin A, vitamin D, thiamine, riboflavin, pyridoxine, niacinamide, dexpanthenol, vitamin E, vitamin K, folic acid, biotin, and vitamin B12 (2.1) Supplied as a single-dose vial of lyophilized powder for reconstitution intended for administration by intravenous infusion after dilution. (2.1) Recommended daily dosage is based on patient's actual weight (2.2) Less than 1 kg: The daily dose is 1.5 mL 1 kg to 3 kg: The daily dose is 3.25 mL 3 kg or more: The daily dose is 5 mL One daily dose of the reconstituted solution (1.5 mL, 3.25 mL or 5 mL) is then added directly to the intravenous fluid (2.2,2.3) See Full Prescribing Information for reconstitution instructions (2.3) Monitor blood vitamin concentrations (2.4) See Full Prescribing Information for drug incompatibilities (2.5) DOSAGE FORMS AND STRENGTHS M.V.I.
    [Show full text]
  • Vitamin A, E, & D Unit Change
    Vitamin A, E, & D Unit Change Agenda The following provides an overview of the updated units that NQAC Dublin will be using to adhere to FDA guideline changes regarding Nutrition and Supplement Facts labels. This presentation will review: • FDA Guidelines • Methods Affected • Unit Changes by Vitamin • Conversions In August of 2019, the FDA updated its guideline requirements for Nutrition and Supplement Facts labels regarding vitamin A, vitamin D, and vitamin E. The following link can be used to access the FDA guidelines directly: www.fda.gov/regulatory-information Which methods are affected by this change? • LI-00.608 –Multi Fat • LI-03.701 –Fat Soluble Vitamin Determination in Premixes • LI-00.683- Carotene • GOP-756-1001- Total Vitamin A by Calculation (will be obsoleted) FDA Provided Unit Conversion Table: Vitamin A The previous RDI for vitamin A was expressed in International Units (IU), a measurement based on the biological activity or effect, where one IU of vitamin A activity had been defined as equal to 0.30 mcg of all-trans-retinol or 0.60 mcg of all-trans-β-carotene The new unit of measure, RAE, considers the vitamin A activity of β-carotene in supplements to be half the activity of pre-formed retinol, and the vitamin A activity of dietary β-carotene to be one- sixth of the β-carotene in supplements Furthermore, carotenoids, such as β-carotene, added to food is assumed to have the same bioconversion as those naturally occurring in foods (12:1). For the other dietary provitamin A carotenoids, β-cryptoxanthin and α-carotene, the RAE is set at 24 based on a vitamin A activity approximately half of that for β-carotene.
    [Show full text]
  • A Clinical Update on Vitamin D Deficiency and Secondary
    References 1. Mehrotra R, Kermah D, Budoff M, et al. Hypovitaminosis D in chronic 17. Ennis JL, Worcester EM, Coe FL, Sprague SM. Current recommended 32. Thimachai P, Supasyndh O, Chaiprasert A, Satirapoj B. Efficacy of High 38. Kramer H, Berns JS, Choi MJ, et al. 25-Hydroxyvitamin D testing and kidney disease. Clin J Am Soc Nephrol. 2008;3:1144-1151. 25-hydroxyvitamin D targets for chronic kidney disease management vs. Conventional Ergocalciferol Dose for Increasing 25-Hydroxyvitamin supplementation in CKD: an NKF-KDOQI controversies report. Am J may be too low. J Nephrol. 2016;29:63-70. D and Suppressing Parathyroid Hormone Levels in Stage III-IV CKD Kidney Dis. 2014;64:499-509. 2. Hollick MF. Vitamin D: importance in the prevention of cancers, type 1 with Vitamin D Deficiency/Insufficiency: A Randomized Controlled Trial. diabetes, heart disease, and osteoporosis. Am J Clin Nutr 18. OPKO. OPKO diagnostics point-of-care system. Available at: http:// J Med Assoc Thai. 2015;98:643-648. 39. Jetter A, Egli A, Dawson-Hughes B, et al. Pharmacokinetics of oral 2004;79:362-371. www.opko.com/products/point-of-care-diagnostics/. Accessed vitamin D(3) and calcifediol. Bone. 2014;59:14-19. September 2 2015. 33. Kovesdy CP, Lu JL, Malakauskas SM, et al. Paricalcitol versus 3. Giovannucci E, Liu Y, Rimm EB, et al. Prospective study of predictors ergocalciferol for secondary hyperparathyroidism in CKD stages 3 and 40. Petkovich M, Melnick J, White J, et al. Modified-release oral calcifediol of vitamin D status and cancer incidence and mortality in men.
    [Show full text]
  • Structure & Function: Lipids and Membranes
    Structure & Function: Lipids and Membranes Lipids vironment of the body requires special struc- Lipids are a diverse group of molecules tures. Other, amphipathic lipids, such as that all share the characteristic that glycerophospholipids and sphin- at least a portion of them is hy- YouTube Lectures golipids spontaneously organize drophobic. Lipids play many by Kevin themselves into lipid bilayers HERE & HERE roles in cells, including serving as when placed in water. Interest- energy storage (fats/oils), constitu- ingly, major parts of many lipids can ents of membranes (glycerophospholipids, be derived from acetyl-CoA. sphingolipids, cholesterol), hormones (steroids), vitamins (fat soluble), oxygen/ Fatty acids electron carriers (heme), among others. For The most ubiquitous lipids in cells are the lipids that are very hydrophobic, such as fats/ fatty acids. Found in fats, glycerophos- oils, movement and storage in the aqueous en- pholipids, sphingolipids and serving as as 220 Figure 2.190 - Saturated fatty acid Figure 2.191 - Arachidonic acid - A (stearic acid) and unsaturated fatty acid polyunsaturated fatty acid (oleic acid) Wikipedia membrane anchors for proteins and other biomolecules, fatty acids are important for en- ergy storage, membrane structure, and as pre- cursors of most classes of lipids. Fatty acids, as can be seen from Figure 2.190 are charac- terized by a polar head group and a long hy- drocarbon tail. Fatty acids with hydrocarbon tails that lack any double bonds are described as saturated, while those with one or more double bonds in their tails are known as un- saturated fatty acids. The effect of double bonds on the fatty acid tail is to introduce a kink, or bend, in the tail, as shown for oleic acid.
    [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]