PEDIATRIC PHARMACOTHERAPY a Monthly Newsletter for Health Care Professionals from the University of Virginia Children’S Hospital

Total Page:16

File Type:pdf, Size:1020Kb

PEDIATRIC PHARMACOTHERAPY a Monthly Newsletter for Health Care Professionals from the University of Virginia Children’S Hospital PEDIATRIC PHARMACOTHERAPY A Monthly Newsletter for Health Care Professionals from the University of Virginia Children’s Hospital Volume 1 5 Number 6 June 20 09 Preven tion and Management of Vitamin D Deficiency in Children : Part II. Vitamin D Supplementation Marcia L. Buck, Pharm.D., FCCP he previous issue of Pediatric Pharmacokinetics T Pharmacotherapy reviewed recent studies Oral v itamin D supplements are well -absorbed documenting the prevalence of vitamin D from the small intestine . The presence of bile is deficiency and the need to increase dietary necessary for absorption. Cholecalciferol vitamin D intake. Several papers published appears to be more rapidly and completely within the last five years have highlighted the absorbed than ergocalciferol. Circulating growing incidence of vitamin D deficiency, vitamin D is bound to serum proteins and is defined as a serum hydroxyvitamin D [ 25(OH)D ] widely distributed throughout the body . It is level less than 20 ng/mL, in infants, children, and stored primarily in the liver and fat .5-7 adolescents world -wide .1,2 As a result of these epidemiologic studies and new information on Both forms of vitamin D are inactive and must the role of vitamin D in preventing autoimmune undergo conversion in the liver and kidneys to diseases, cardiovascular disease, and cancer , the form biologically active compounds. American Academy of Pediatrics (AAP) and the Ergocalciferol and cholecalciferol are Lawson Wilkins Pediatric Endocrine Society hydroxylated by hepatic microsomal enzymes to have published updated guidelines which 25(OH)D , also referred to as calcifediol . recommend increasing the daily intake of vitamin Further conversion of th is intermediate form in D to 400 International Units for infants and the kidney s produces the physiologically active children. 3,4 Vitamin D supplements may be form, 1,25 -dihydroxy vitamin D , or calcitriol . necessary for those patients unable to meet this Vit amin D products are primarily eliminated st andard with dietary intake alone, including through excretion in the bile. The mean breast -fed infants. This issue of the newsletter elimination half -li fe of 1,25 -dihydroxyvitamin D will review the pharmacology of oral vitamin D is 5 to 8 hours in adults .5-7 supplements and provide recommendations for dosing and monitoring. Although it is not the biologically active form , the intermediate form, 25(OH)D, is used to Vitamin D Supplements assess vitamin D status since 1,25 - Exogenous vitamin D i s available as a dietary dihydroxyvitamin D levels do not typically supplement in two forms: ergocalciferol (vitamin decrease until clinical symptoms of vitamin D D2), derived from the irradiation of ergosterol in deficiency ha ve become severe. The yeast, and cholecalciferol (vitamin D 3), obtained intermediate 25( OH)D for m also has a longer from animal sources. The two forms are half -life (approximately 15 days) and is less regarded as equivalent in most dosing res ources, affected by parathyroid hormone, calcium, or with 1 mcg of either providing 40 International phosphate levels. There is a lag time of 10 to 24 Units of vitamin D activity. Several recent hours after administration of exogenous vitamin sources, however, suggest that cholecalciferol is D2 or D 3 until the biologically active forms have better absorbed and may raise serum 25(OH)D been produced. Maximum clinical response levels up to three -fold higher than ergocalciferol typically occurs approximately a month after in adults , produc ing more long -lasting therapy has been initiated. Pharmacologic physiologic results .3-7 effects may continue for more than 2 months after vitamin D administration. 5-7 Warnings and Precautions those consuming less than 1 L of infant Vitamin D su pplements are contraindicated in formula/day should receive 400 International patients with hypercalcemia or a known Units/day of an oral liquid vitamin D product. 3,4 hypersensitivity to any component of the product. The Lawson Wilkins Pediatric Endocrine Society Some vitamin D supplements contain tartrazine recommends that p reterm infants should receive (FD&C yellow dye no. 5) and may produce a 400 to 800 International Units of vitamin D (10 hypersensitivity reaction in susceptible to 20 mcg) per day to compensate for decreased indi viduals. Patients taking vitamin D placental transfer in utero and decreased supplements in doses above the recommended gastrointestinal absorption after birth .4 daily dietary intake should be monitored for hypercalcemia, impaired renal function, or other For treatment of documented vitamin D evidence of vitamin D toxicity. 5-7 deficiency, infants may be given 1,000 to 2,000 International Units/day (25 to 50 mcg) and older Adverse Effects children may be given up to 5,000 International Excessive administration of v itamin D may result Units/day (125 mcg) for 2 t o 3 months .4,8 A in weakne ss, hea dache , somnolence, nausea, variety of alternative dosing regimens have been vomiting, dry mouth, a metallic taste, published over the past decade. A high -dose co nstipation, muscle or bone pain. With short -course r egimen providing a total of continued high -dose vitamin D intake (> 10,000 100,000 to 600,000 International Units (2.5 to 15 International Units/day) or overdose (serum mg) over 1 to 5 days has been suggested for 25(OH)D levels > 100 ng /mL) , patients may patients who might not adhere to longer develop polyuria, polydipsia, anorexia, regimens. 4 irritability, mild acidosis, hypercalciuria, anemia, azotemia, nephrocalcinosis, vascular Vitamin D dosing in children with kidney disease calcifications, pancreatitis, photophobia, or other chronic illnesses shoul d be based on rhinorrhea, pruritus, hyperthermia, serum 25(OH)D levels . Table 1 provides general cardiovascular instability, bone demineralization, recommendations for these patients . Table 2 lists and hepatic or renal dysfunction . The se dosing recommendations for children with severe symptoms may persist for several months after or chronic deficiency states .3-7 discontinuing therapy .5-8 Table 1. Examples of Vitamin D Dosing Based Drug Interactions on Serum 25(OH)D Levels The absorption of vitamin D supplements may be decreased by administration with mineral oil , 25(OH)D Dose cholesty ramine , colestipol, or orlistat . Use of 16 -30 ng/mL 2,000 International Units/day magnesium -containing antacids during vitamin D (50 mcg) or 50,000 supplementation may result in hypermag nesemia, International Units (1.25 mg) especially in renal dialysis patients. 5-7 monthly for 3 months Administration of vitamin D supplements in 5-15 ng/mL 4,000 International Units /day patients with hypoparathyroidism wh o are also (100 mcg) or 50,000 taking thiazide diuretics may produce International Units (1.25 mg) hypercalcemia. Use of vitamin D and calcium every other week for 3 mont hs supplements may antagonize the effects of calcium channel blockers. This combination may < 5 ng/mL 8,000 International Units /day also increase the risk of toxicity in patients taking (200 mcg) or 50,000 digoxin. Administ ration of phenobarbital or International Units (1.25 mg) phenytoin may increase the rate of hepatic weekly for 1 month f ollowed metabolism of vitamin D to inactive compo unds by 4,000 International and reduce calcium absorption .5-7 Units /day or 50,000 International Units every other Dosing Recommendations week for a total of 3 months The current recommendation from both the AAP and the Lawson Wilkins Pediatric End ocrine Table 2. Examples of Vitamin D Dosing Based Society is a minimum dietary intake of 400 on Diagnosis International Units/day (10 mcg/day) for neonates, children, and adolescents. 3,4 If this Diagnosis Dose amount cannot be achieved through their normal Rickets 1,000 -10 ,000 International diet, a vitamin D supplement should be Units/day ( 25 to 25 0 mcg/day) administered. Exclusively bre astfed infants and for 2 to 3 months, followed by maintenance treatment with Summary 400 to 1,000 International Vitamin D supplementation for children has been Units/day the focus of a number of publications within the last year. New demographic data ha ve identified Malabsorption 25,000 International Unit s/day a growing number of children with vitamin D syndromes (625 mcg/day) deficiency at risk for rickets or impaired bone growth and mineralization . In addition, there is Familial hypo - 40,000 -80,000 International growing evidence of the role of vitamin D in the phosphatemia Units /day (1 to 2 mg/day) prevention of autoimmune and cardiovascular diseases, as well as cancer. The AAP and the Hypo para - 200,000 International Lawson Wilkins Pediatric Endocrine Society thyroidism Units /day (5 mg/day) , titrated have recently adopted new standards for daily to maintain optimal levels vitamin D requirements. As a result, more children will need vitamin D supplementation. Vitamin D supplements may be ta ken with or The choice of supplement , as well as dose and without food . A dministration with food may be dosing frequency, vary among references . useful to reduce stomach upset. Calcium Additional research is needed to identify the supplementation (30 to 75 mg/kg/day oral optimal dosing strategy for vitamin D elemental calcium) is often necessary to supplementation in pediatric patients . maximize response in patients with vitamin D deficiency. Patients receivi ng vitamin D References supplementation beyond the recommended daily 1. Gordon CM , Feldman HA, Sinclair L, et al. Prevalence of dietary intake sho uld undergo periodic vitamin D deficiency among healthy infants and toddlers. Arch Pediatr Adolesc Med 2008;162:505 -12. monitoring of serum 25(OH)D levels , using an 2. Saintonge S Bang H, Gerber JM. Implications of a new assay for both 25( OH)D 2 and 25(OH)D 3, as well definition of vitamin D deficiency in a multiracial US as serum calcium, phosphorus, and alkaline adolescent population: the National Health and Nutrition phosphatase at one and th ree months or until Examination Surv ey III.
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]
  • 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]
  • Niacin (Nicotinic Acid) in Non-Physiological Doses Causes Hyperhomocysteineaemia in Sprague–Dawley Rats
    Downloaded from British Journal of Nutrition (2002), 87, 115–119 DOI: 10.1079/BJN2001486 q The Authors 2002 https://www.cambridge.org/core Niacin (nicotinic acid) in non-physiological doses causes hyperhomocysteineaemia in Sprague–Dawley rats Tapan K. Basu*, Neelam Makhani and Gary Sedgwick . IP address: Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, T6G 2P5 Canada (Received 22 September 2000 – Revised 17 July 2001 – Accepted 6 August 2001) 170.106.35.93 Niacin (nicotinic acid) in its non-physiological dose level is known to be an effective lipid- , on lowering agent; its potential risk as a therapeutic agent, however, has not been critically 27 Sep 2021 at 22:43:08 considered. Since niacin is excreted predominantly as methylated pyridones, requiring methionine as a methyl donor, the present study was undertaken to examine whether metabolism of the amino acid is altered in the presence of large doses of niacin. Male Sprague–Dawley rats were given a nutritionally adequate, semi-synthetic diet containing niacin at a level of either 400 or 1000 mg/kg diet (compared to 30 mg/kg in the control diet) for up to 3 months. Supplementation with niacin (1000 mg/kg diet) for 3 months resulted in a significant increase in plasma and urinary total homocysteine levels; this increase was further accentuated in the , subject to the Cambridge Core terms of use, available at presence of a high methionine diet. The hyperhomocysteineaemia was accompanied by a significant decrease in plasma concentrations of vitamins B6 and B12, which are cofactors for the metabolism of homocysteine.
    [Show full text]
  • Dietary Supplements Compendium Volume 1
    2015 Dietary Supplements Compendium DSC Volume 1 General Notices and Requirements USP–NF General Chapters USP–NF Dietary Supplement Monographs USP–NF Excipient Monographs FCC General Provisions FCC Monographs FCC Identity Standards FCC Appendices Reagents, Indicators, and Solutions Reference Tables DSC217M_DSCVol1_Title_2015-01_V3.indd 1 2/2/15 12:18 PM 2 Notice and Warning Concerning U.S. Patent or Trademark Rights The inclusion in the USP Dietary Supplements Compendium of a monograph on any dietary supplement in respect to which patent or trademark rights may exist shall not be deemed, and is not intended as, a grant of, or authority to exercise, any right or privilege protected by such patent or trademark. All such rights and privileges are vested in the patent or trademark owner, and no other person may exercise the same without express permission, authority, or license secured from such patent or trademark owner. Concerning Use of the USP Dietary Supplements Compendium Attention is called to the fact that USP Dietary Supplements Compendium text is fully copyrighted. Authors and others wishing to use portions of the text should request permission to do so from the Legal Department of the United States Pharmacopeial Convention. Copyright © 2015 The United States Pharmacopeial Convention ISBN: 978-1-936424-41-2 12601 Twinbrook Parkway, Rockville, MD 20852 All rights reserved. DSC Contents iii Contents USP Dietary Supplements Compendium Volume 1 Volume 2 Members . v. Preface . v Mission and Preface . 1 Dietary Supplements Admission Evaluations . 1. General Notices and Requirements . 9 USP Dietary Supplement Verification Program . .205 USP–NF General Chapters . 25 Dietary Supplements Regulatory USP–NF Dietary Supplement Monographs .
    [Show full text]