Metabolism II Exam 1 DRIs Existing guides regarding nutrients and food 1 Dietary Guidelines 2010 the newest they refer to either food or macronutrients 2 Food guides a pictorial reference using a plate or pyramid 3 DRI RDA s MINERALS IN GENERAL Mineral classification Essential minerals comprise only 4 5 of total body weight Ca P K Cl Na Mg S 70 kg human g 1200 DRI mg 1000 AI Actual Intake mg 500 1200 660 150 100 100 25 200 700 RDA 4700 AI 2300 AI 1500 AI 1000 1500 2000 5000 3000 9000 3000 18000 320 420 RDA 180 480 Function 99 in bones and teeth 1 in serum Bones teeth proteins Electrolytes water and pH balance Electrolytes water and pH balance Electrolytes water and pH balance Bone nerves and enzymes Protein strutucture Metabolism II Exam 1 Macrominerals microminerals and ultratrace minerals Macro more than 100mg a day Calcium Phosphorus Magnesium Chloride Potassium Sodium Micro Chromium Selenium Iodine Molybdenum Silicone Manganese Fluorine Trace less than 12mg a day Zinc Iron Manganese Copper Iodine Selenium Essentiality required to support adequate growth reproduction and health throughout the life cycle when all other nutrients are optimal Deficiency will cause changes in some organs or tissues before than in others and depending on species They all can be toxic Ratio between the minimal toxic level to the adequate level useful index of relative toxicity Metabolism II Exam 1 At concentrations between the safe and toxic levels there may be a pharmacological effect of the element and the question is at what levels if any do minerals act as pharmacologic rather than essential or toxic agent Microminerals primarily in catalytic functions although they might exert some other roles Iron is involved in cytochromes and enzymes for electron transport systems but it is also a structural part of hemoglobin and a component of numerous proteins that have critical roles in energy metabolism Cu deficiency gives rise to many pathologies that can be identified with specific cuproenzymes depigmentation and low tyrosinase activity or aortic rupture and low lysyl oxidase activity Mn deficiency causes reproductive failure skeletal deformities and ataxia it s a component of superoxide dismutase pyruvate carboxylase arginase although these enzymes may not be related directly to the observed pathology of Mn deficiency Zn deficiency causes stunted growth skin lesions reproductive difficulties It has a structural role as a part of protein involved in gene expression transcription Zn finger proteins It is a component of enzymes that catalyze more than 50 reactions Mo is component of xanthine oxidase and sulfite oxidase Se deficiency results in severe pathology including cardiomyopathy and skeletal muscle defects It is also a component of several proteins glutathione peroxidases Co is component of vitamin B12 there is no evidence that it has any other function Iodine is an important component of the thyroid gland hormones its deficiency causes goiter and cretinism F functions as protective rather than catalytic agent It is a structural component of teeth and bones there is no evidence that it exerts a specific biochemical function Bioavailability is decreased by Chelation Competition in absorption or transport Other antagonists Bioavailability can be improved by Other food constituents Metabolism II Exam 1 Intestinal environment Synergism Gut The Powerhouse 1 16 ft in length 2 Includes a Oral cavity esophagus stomach and small and large intestine b Accessory organs i Pancreas liver gallbladder 3 Food is passed from the mouth through pharynx into esophagus 4 Esophagus is about 10 in long 5 The stomach mixes the food with digestive juices and enzymes and then holds partially digested food before releasing it in small quantities into lower gastrointestinal tract 6 When empty stomach is about 50 ml 2 oz 7 When full it is 1 to 1 5 L 37 52 oz 8 Small Intestine surface area 300 m2 or 3 football fields in length a Represents the main site for nutrient absorption b Duodenum 1 ft long i Receives secretions from pancreas liver and gallbladder c Jejunum and ileum 9 ft long i The epithelial lining of the small intestine or MUCOSA is structured to maximize surface area and thus the ability to absorb nutrients d Contributing to this large surface are cells i Villous cells projecting into the lumen and consisting of hundreds of ENTEROCYTES absorptive epithelial ii Microvilli hairlike extensions of the enterocytes that make up the villi 9 Ultimately the enterocytes will be sloughed off into the lumen and excreted into feces a The turnover occurs every 3 5 days b All released material from sloughed off cells including vitamins and minerals will have a chance to be reabsorbed back into the circulation as ENDOGENOUS secretions 10 LARGE INTESTINE about 5 ft long a Unabsorbed material from ileum empties into the caecum large intestine b Thereafter the material moves along ascending into traversing down to descending and finally into the sigmoid colon Metabolism II Exam 1 OSTEOPOROSIS Osteoporosis is a skeletal disorder characterized by compromised bone strength leading to increased risk of fractures DXA Bone density scan it measures the bone density to see if you have osteoporosis How is it diagnosed 1 Medical History Risk factor assessment 2 Physical Exam Height assessment 3 Lab Tests as appropriate Metabolism II Exam 1 4 Bone mineral density measurements Nutrition and Bone 1 Protein is necessary for collagen formation and maintenance the higher the protein intake the higher the urinary calcium exretion Daily recommendations for protein are 8g kg body weight 2 Sodium increases urinary calcium excretion The daily recommendation AI for older adults is 1 300mg day but the average intake s about 4000 mg day Treatment Supplement with calcium and vitamin D and weight bearing exercises as a lifestyle practice and in addition to any other treatment Pharmacological treatment agents Antiresorptive and Anabolic 1 Antiresorptive agents a Estrogen discontinued after 2002 WHI study results b Biosphosphates postmenopausal osteoporosis i Etidronate not in US ii Chlordronate not in US iii Alendronate Fosamax daily weekly iv Risedronate Actonel daily weekly monthly v vi vii viii Zoledronic Acid Reclast annual ix Pamidronate quarterly off label Ibandronate Boniva daily monthly IV Ibandronate Boniva quarterly c SERMS Selective Estrogen Receptor Modulators d Anti Rank Ligand Antibody Denosumab Prolia e Cathepsin K Inhibitors 2 Anabolic Agents
View Full Document
Unlocking...