Micronutrients Metabolism Objectives Distinguish between and identify fat
Micronutrients & Metabolism
Objectives � Distinguish between and identify fat- and watersoluble vitamins � Understand the general role of B-vitamins and minerals discussed in the lecture � Know the 3 major vitamin coenzymes identified with metabolism � Identify major B-vitamin deficiencies � Recognize major minerals involved in macronutrient metabolism
Vitamins � Used to regulate body processes � Contain carbon � Almost everyone who eats a healthful diet will readily meet their needs from food alone � Fat Soluble & Water Soluble
Fat Soluble Vitamins � , , , & . � Found in foods with � Stored in � Deficiency? and absorbed with it , so it can be toxic ◦ ◦ Causes osteoporosis, night vision loss
Water Soluble Vitamins � Filtered and excreted by the kidney � Vitamin C � B-Vitamins ◦ Thiamin (B 1), Riboflavin (B 2), Niacin, Pyridoxine (B 6), Folate, Cobalamin (B 12), pantothenic acid, biotin � Found � Only in grains, fruit, vegetables, meat, dairy B 12 is stored in large amounts ◦ Increased risk of .
Minerals � Do not contain C and are not changed by digestion � Major ◦ 100 mg + required a day, in body at 5 g or more ◦ � Trace ◦ ◦ Selenium, fluoride, iodine, chromium, manganese, iron, zinc
Absorption Varies Examples: � Iron ◦ Heme ( ◦ Non-heme ( �Inhibitors: �Enhancers: � Calcium ) ) 25% absorbed 3 -5% absorbed ◦ Dairy - absorbed 30 -35% ◦ Vegetables - much less because of binding
Vitamins important in metabolism � Thiamin, riboflavin, niacin, folate, B 12, pantothenic acid � Coenzymes: � Nutrient Transport � Hormone production & metabolic regulation ◦ Ex: thyroid H & iodine
� Coenzyme form Thiamin (B 1) ◦ Converts pyruvate . ◦ Converts BCAA’s to C-skeleton for TCA ◦ DNA/RNA production � RDA easily met ◦ Who might need more? � Deficiency ◦ Beri-beri �Nerve damage & heart failure ◦ Wernicke-Korsakoff �Tremors, confusion, poor memory
Riboflavin (B 2) � Coenzymes FAD, FMN ◦ Aid in ATP production � RDA easily met in US ◦ , eggs, organ meat, broccoli, grains, cereal ◦ Light sensitive � Deficiency - ◦ Affects throat, mouth, lips, tongue ◦ Severe: impaired B 6 and niacin use
Niacin � Coenzymes ◦ Nicotinic Acid (NAD), Nicotinamide (NADP) ◦ � RDA � Sources: meat, fish poultry, enriched cereal � Excess? � UL 35 mg/day � Deficiency: ◦ 4 D’s: Pellagra
B 6 (Pyridoxine) � Pyridoxine, � Phosphate Pyridoxal, Pyridoxamine Forms are active (PNP, PLP, PMP) ◦ Gluconeogenesis ◦ Convert glycogen ◦ Protein metabolism � RDA easily met ages 19 -50 ◦ May be based on protein intake
� Sources ◦ Meat, fish, poultry ◦ Cereal, potato & starchy vegetables, fortified soy �Typical Diet is 40% from animal/60% from plant � Excess ◦ Causes neuropathy, dermatological lesions ◦ UL 100 mg/d ◦ Supplement’s may treat PMS & carpal tunnel � Deficiency ◦ Anemia, convulsions, depression ◦ Increased need with alcoholism, high activity, arthritis, vascular disease
Pantothenic Acid � Coenzyme A (Co. A), Acyl Carrier Protein (ACP) ◦ Synthesize fatty Acids �Storage, oxidation, ketone production ◦ Synthesize cholesterol ◦ Drug detoxification � Deficiency is rare ◦ Found in eggs, chicken, beef, potato, oats, tomato, grains ◦ Excess shows no toxicity
� Part of 4 enzymes Biotin ◦ CO 2 carrier ◦ Used in fat synthesis, gluconeogenesis, macronutrient metabolism � Contained in few foods ◦ Egg yolk, organ meat, cooked oats, soy, nuts, milk � No known toxicity effects � Deficiency seen with raw egg white consumption and Total parenteral nutrition (TPN) ◦ Hair thinning & color loss, depression, hallucination, scaly rash around eyes, mouth, nose,
� Vitamin-like Choline functions ◦ Formation of lipoproteins & cell membranes ◦ Essential to fat & cholesterol transport ◦ Synthesizes acetylcholine �important for � Men � In � & . need more than women cell membranes of food Liver, milk, eggs, peanuts � Toxicity ◦ Fishy odor, vomiting, salivation, low blood pressure
� Functions ◦ Synthesis of Iodine hormones (T 3 & T 4) �Excess will block synthesis ◦ Regulates: � Sources ◦ voluntarily added to ; ◦ Plants, saltwater fish, water � Thyroid may enlarge causing a � Deficiency . ◦ growth, mental & neurologic disorders, decreased fertility, prenatal/infant death �Cretinism- mental retardation at birth
� Hypothyroidism ◦ Body Temp. ◦ Weight gain, fatigue & sluggishness � 2. 2 billion people suffer from deficiency ◦ Goiter treated with iodized salt � Hyperthyroidism ◦ Caused primarily by Grave’s disease �Autoimmune; causes TH overproduction ◦ Weight loss, increased heat production, muscle tremor, rapid heart rate, eye protrusion
Chromium � Carbohydrate metabolism ◦ Aids in action of to transport glucose ◦ Metabolism of DNA/RNA, immunity, growth � Supplements? � Sources: ◦ Mushrooms, dark chocolate, nuts, whole grains, cereal, asparagus, some beers, red wine, processed meat
Manganese � Cofactor � Forms in macronutrient metabolism cartilage in joints � Produces � Best antioxidant enzymes sources ◦ Whole grains, pineapple, pine nuts, okra, raspberries, spinach, tea � Toxicity if: ◦ Inhaling manganese dust, drinking high manganese water �Impairs neuromuscular system (UL 11 mg/day) � Deficiency rare: ◦ Poor growth & reproduction, low bone density, poor glucose/lipid breakdown, dermatitis
� Component of thiamin and biotin � Part of protein shapes � Required � There , stabilizing 3 -D by liver to process alcohol & drugs � Important � Found Sulfur in balance in protein containing foods is no DRI set
Inadequate B-Vitamin Intake sufficient to prevent deficiency but not to fully supply metabolic pathways � Intake � Studies have shown a 7 -12% decrease in physical abilities � What if thiamin, riboflavin, and B 6 are low in athletes? ◦
Diets low in B-Vitamins � Diets high in processed foods � Alter the following day to increase B-vitamins ◦ Breakfast: white roll, margarine, jelly, coffee with sugar ◦ Lunch: grilled cheese on white bread, iceburg lettuce salad ◦ Dinner: white rice & stir-fried vegetables (green peas, carrots, zucchini) ◦ Snacks: cola, chocolate chip cookies, popcorn
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