Water-Soluble Vitamins

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B1, B2, B12, Folate, B6 and C

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Water-Soluble Vitamins: 

Water-Soluble Vitamins 11/25/2011 Dr.N.B.Reddy CMCH & RC Dr.N.Bayapa Reddy ASST.PROFESSOR COMMUNITY MEDICINE CHENNI MEDICAL COLLEGE HOSPITAL & RESEARCH CENTER

Water Soluble Vitamins: 

Water Soluble Vitamins Thiamin Pantothenic Acid Riboflavin Biotin Niacin Vitamin C Vitamin B-6 Folate Vitamin B-12 11/25/2011 Dr.N.B.Reddy CMCH & RC

Fat vs. Water Soluble Vitamins: 

Fat vs. Water Soluble Vitamins Criteria Water Soluble Fat Soluble Absorption Directly to blood Lymph via CM Transport free Require carrier Storage Circulate freely In cells with fat Excretion In urine Stored with fat Toxicity Possible w supplements Likely w supplements Requirements Every 2-3 days Every week 11/25/2011 Dr.N.B.Reddy CMCH & RC

Overview of Water-Soluble Vitamins: 

Overview of Water-Soluble Vitamins Dissolve in water Generally readily excreted Subject to cooking losses Function as a coenzyme Participate in energy metabolism 50-90% of B vitamins are absorbed Marginal deficiency more common 11/25/2011 Dr.N.B.Reddy CMCH & RC

Thiamine losses: 

Thiamine losses Many nutrients lost in the process of milling the grain/cereal. Eg; Thiamin, riboflavin, niacin, folate , iron Long storage of fruits and vegetables Whole grains contain original nutrients 11/25/2011 Dr.N.B.Reddy CMCH & RC

Thiamin: 

Thiamin Contains sulfur and nitrogen group Destroyed by alkaline and heat Coenzyme: Thiamin pyrophosphate (TPP) 11/25/2011 Dr.N.B.Reddy CMCH & RC

Food Sources of Thiamin: 

Food Sources of Thiamin Enriched grains/ whole grains Milk is important source for infants White bread, pork, hot dogs, luncheon meat, cold cereal contains smaller amounts Thiaminase found in raw fish 11/25/2011 Dr.N.B.Reddy CMCH & RC

Absorption, Transport, Metabolism of Thiamin: 

Absorption, Transport, Metabolism of Thiamin Absorbed in the jejunum by a carrier-mediated system Transported by RBC in the blood Excess quickly excreted in the urine 11/25/2011 Dr.N.B.Reddy CMCH & RC

Coenzyme: Thiamin Pyrophosphate (TPP): 

Coenzyme: Thiamin Pyrophosphate (TPP) Synthesis of neurotransmitter Convert pyruvate to acetyl- CoA CoA NAD + NADH + H + Glucose Pyruvate Acetyl- CoA Citric Acid Cycle CO 2 11/25/2011 Dr.N.B.Reddy CMCH & RC

RDA For Thiamin: 

RDA For Thiamin 0.5 mg per 1000 kcals of energy intake 1.1 mg/day for women 1.2 mg/day for men Most exceed RDA in diet Surplus is rapidly lost in urine; non toxic 11/25/2011 Dr.N.B.Reddy CMCH & RC

Who is at Risk For Deficiency?: 

Who is at Risk For Deficiency? Poor people Alcoholics, alcohol interferes with absorption of B1 ( Wernicke-Korsakoff syndrome) Elderly, risk for not eating sufficient energy. Diet consisting of highly processed (polished) foods 11/25/2011 Dr.N.B.Reddy CMCH & RC

Deficiency of Thiamin: 

Deficiency of Thiamin Occurs where rice is the only staple Dry beriberi Weakness, nerve degeneration, irritability, poor arm/leg coordination, loss of nerve transmission and memory loss Wet beriberi Impaired cardiac function, enlarge heart, heart failure, Edema. Impaired muscle contractions and muscle twitches 11/25/2011 Dr.N.B.Reddy CMCH & RC

Riboflavin: 

Riboflavin Coenzymes: Flavin mononucleotide ( FMN ) Flavin adenine dinucleotide ( FAD ) Oxidation-reduction reaction (glutathione peroxidases ) Electron transport chain Citric Acid Cycle Catabolism of fatty acids Remove ammonia during deamination of some amino acids 11/25/2011 Dr.N.B.Reddy CMCH & RC

Food Sources of Riboflavin: 

Food Sources of Riboflavin Liver and meat Milk/products Enriched grains, germination increases riboflavin level in pulses Green leafy vegetables Sensitive to Uv radiation (sunlight) Stored in paper, opaque plastic containers HCL in the stomach release riboflavin from its bound forms Transported by a protein carrier in the blood 11/25/2011 Dr.N.B.Reddy CMCH & RC

RDA for Riboflavin: 

RDA for Riboflavin 0.6 mg per 1000 kcals of energy intake 1.1 mg/day for women 1.3 mg/day for men Average intake is above RDA toxicity not documented 11/25/2011 Dr.N.B.Reddy CMCH & RC

Who is at Risk For Deficiency?: 

Who is at Risk For Deficiency? Population where rice is the staple food Low milk/dairy intake Alcoholics Long term use of phenobarbitone 11/25/2011 Dr.N.B.Reddy CMCH & RC

Deficiency of Riboflavin: 

Deficiency of Riboflavin Ariboflavinosis Most common lesion associated is stomatitis , other signs are cheilosis , glossitis , seborrheic dermatitis, eye disorder, throat disorder, nervous system disorder Usually in combination with other deficiencies 11/25/2011 Dr.N.B.Reddy CMCH & RC

Glossitis: 

Glossitis 11/25/2011 Dr.N.B.Reddy CMCH & RC

Niacin: 

Niacin Nicotinic acid (niacin) is essential for the carbohydrate metabolism. Coenzyme Nicotinamide adenine dinucleotide ( NAD ) Nicotinamide adenine dinucleotide phosphate ( NADP ) Made from tryptophan; essential nutrient if protein intake is inadequate 60 mg tryptophan convert into 1 mg niacin RDA is 14-16 NE/day for adults 11/25/2011 Dr.N.B.Reddy CMCH & RC

Food Sources of Niacin: 

Food Sources of Niacin 11/25/2011 Dr.N.B.Reddy CMCH & RC Liver, kidney, beef, chicken, turkey. Mushrooms Enriched grains Heat stable; little cooking loss Milk is poor source

Deficiency of Niacin: 

Deficiency of Niacin Pellagra 3 Ds Diarrhoea, dermatitis, dementia. Occurs in 50-60 days Decrease appetite & weight Prevented with an adequate protein diet Enrichment Act of 1941 Only dietary deficiency disease to reach epidemic proportions in the U.S. Who is at risk? (Untreated) corn as main staple, poor diet, Hartnup disease, alcoholics 11/25/2011 Dr.N.B.Reddy CMCH & RC

Dermatitis of Pellegra: 

Dermatitis of Pellegra 11/25/2011 Dr.N.B.Reddy CMCH & RC

Niacin as a Medicine: 

Niacin as a Medicine 75-100 x RDA can lower LDL and TG and increase HDL Slow/ reverse progression of atheroscelerosis with diet and exercise Toxicity effects Flushing of skin, itching, nausea, liver damage 11/25/2011 Dr.N.B.Reddy CMCH & RC

Pantothenic Acid: 

Pantothenic Acid Part of Coenzyme-A Essential for metabolism of CHO, fat, protein Glucose Fatty acids Acetyl-CoA Amino Acids Alcohol 11/25/2011 Dr.N.B.Reddy CMCH & RC

Food Sources of Pantothenic acid: 

Food Sources of Pantothenic acid Meat Milk Mushroom Liver Peanut Adequate Intake = 5 mg/day Average intake meets AI 11/25/2011 Dr.N.B.Reddy CMCH & RC

Deficiency of Pantothenic Acid: 

Deficiency of Pantothenic Acid Rare Burning foot syndrome, listlessness, fatigue, headache, sleep disturbance, nausea, abdominal distress Alcoholics at risk Usually in combination with other deficiencies 11/25/2011 Dr.N.B.Reddy CMCH & RC

Biotin: 

Biotin Free and bound form Biocytin (protein bound form) Biotinidase in small intestine Metabolism of CHO, fat, protein (C skeleton) DNA synthesis 11/25/2011 Dr.N.B.Reddy CMCH & RC

Food Sources of Biotin: 

Food Sources of Biotin Cauliflower, yolk, liver, peanuts, cheese Intestinal synthesis of biotin Biotin content only available for a small number of foods Avidin inhibits absorption, > 1 dozen raw eggs consumption per day. 11/25/2011 Dr.N.B.Reddy CMCH & RC

Biotin Needs: 

Biotin Needs Adequate Intake is 30 ug/day for adults This may overestimate the amount needed for adults No Upper Limit for biotin 11/25/2011 Dr.N.B.Reddy CMCH & RC

Who is at Risk For Deficiency?: 

Who is at Risk For Deficiency? Rare High intake of raw egg white diet Alcoholics Biotinidase deficiency Anticonvulsant drug use Signs & symptoms: skin rash, hair loss, convulsion, neurological disorders, impaired growth in children 11/25/2011 Dr.N.B.Reddy CMCH & RC

Vitamin B-6: Pyridoxal, Pyridoxine, Pyridoxamine: 

Vitamin B-6: Pyridoxal , Pyridoxine, Pyridoxamine Main coenzyme form: pyridoxal phosphate ( PLP ) Activate enzymes needed for metabolism of CHO, fat , protein Synthesis of hemoglobin and oxygen binding and white blood cells Synthesis of neurotransmitters INH is antagonist for pyridoxine 11/25/2011 Dr.N.B.Reddy CMCH & RC

Food Sources of Vitamin B-6: 

Food Sources of Vitamin B-6 Meat, fish, poultry Whole grains (not enriched back) Banana Spinach Avocado Potato 11/25/2011 Dr.N.B.Reddy CMCH & RC

RDA for Vitamin B-6: 

RDA for Vitamin B-6 1.3 mg/day for adults 1.7 mg/day for men over 50 1.5 mg/day for women over 50 Daily Value set at 2 mg Average intake is more than the RDA 11/25/2011 Dr.N.B.Reddy CMCH & RC

Deficiency of Vitamin B-6: 

Deficiency of Vitamin B-6 Microcytic hypochromic anemia Seborrheic dermatitis Convulsion, depression, confusion Reduce immune response Peripheral nerve damage 11/25/2011 Dr.N.B.Reddy CMCH & RC

B-6 As A Medicine?: 

B-6 As A Medicine? PMS B-6 to increase the level of serotonin Improve depression Not a reliable treatment Carpal tunnel syndrome Toxicity potential Can lead to irreversible nerve damage with > 200 mg/day 11/25/2011 Dr.N.B.Reddy CMCH & RC

Folate (Folic acid, Folacin): 

Folate (Folic acid, Folacin) Consists of pteridine group, para-aminobenzoic acid (PABA), and glutamic acid Coenzyme form: tetrahydorfolic acid ( THFA ) 11/25/2011 Dr.N.B.Reddy CMCH & RC

Food Sources of Folate: 

Food Sources of Folate Liver Fortified breakfast cereals Grains, legumes Foliage vegetables Susceptible to heat, oxidation, ultraviolet light 11/25/2011 Dr.N.B.Reddy CMCH & RC

Absorption, Metabolism of Folate: 

Absorption, Metabolism of Folate Absorbed in the monoglutamate form with help of folate conjugase Actively absorbed during low to moderate intake Passively absorbed during high intake Delivered to the liver where it is changed back to the polyglutamate form Mostly stored in the liver Excreted in the urine and bile (enterohepatic circulation) 11/25/2011 Dr.N.B.Reddy CMCH & RC

Functions of Folate: 

Functions of Folate DNA synthesis Transfer of single carbon units Synthesis of adenine and guanine Anticancer drug methotrexate Homocysteine metabolism Neurotransmitter formation 11/25/2011 Dr.N.B.Reddy CMCH & RC

RDA for Folate: 

RDA for Folate Healthy adults 100 ug /day Pregnancy 400 ug /day Lactation 150 ug /day Children 100 ug /day 11/25/2011 Dr.N.B.Reddy CMCH & RC

Deficiency of Folate: 

Deficiency of Folate Similar signs and symptoms of vitamin B-12 deficiency Pregnant women Alcoholics Interferes with the enterohepatic circulation of bile/folate 11/25/2011 Dr.N.B.Reddy CMCH & RC

Megaloblastic Anemia (Fig. 10-7): 

Megaloblastic Anemia (Fig. 10-7) 11/25/2011 Dr.N.B.Reddy CMCH & RC

Neural Tube Defects: 

Neural Tube Defects Spina bifida Anencephaly Importance of folate before and during pregnancy 11/25/2011 Dr.N.B.Reddy CMCH & RC

Toxicity of Folate: 

Toxicity of Folate Epilepsy Skin, respiratory disorder FDA limits nonprescription supplements to 400 ug per tablet for non-pregnant adults OTC Prenatal supplement contains 800 ug Excess can mask vitamin B-12 deficiency 11/25/2011 Dr.N.B.Reddy CMCH & RC

Vitamin B-12: 

Vitamin B-12 Cyanocobalamin. methlcobalamin, 5-deoxyadenosylcobalamin Contains cobalt Folate metabolism Maintenance of the myelin sheaths Rearrange 3-carbon chain fatty acids so can enter the Citric Acid Cycle 11/25/2011 Dr.N.B.Reddy CMCH & RC

Food Sources of Vitamin B-12: 

Food Sources of Vitamin B-12 11/25/2011 Dr.N.B.Reddy CMCH & RC Synthesized by bacteria, fungi and algae (Stored primarily in the liver) Animal products Organ meat Seafood Eggs Hot dogs Milk

Absorption of Vitamin B-12 (Fig. 10-10) : 

Absorption of Vitamin B-12 (Fig. 10-10) 11/25/2011 Dr.N.B.Reddy CMCH & RC

Therapy for Ineffective Absorption: 

Therapy for Ineffective Absorption Many factors can disrupt this process Monthly injections of vitamin B-12 Vitamin B-12 nasal gel Megadoses of vitamin B-12 to allow for passive diffusion 11/25/2011 Dr.N.B.Reddy CMCH & RC

Functions of Vitamin B-12: 

Functions of Vitamin B-12 Helps convert methylmalonyl CoA to succinyl CoA (citric acid cycle) RBC formation Nerve functions Maintains myelin sheath Megalobalstic anemia 11/25/2011 Dr.N.B.Reddy CMCH & RC

RDA for Vitamin B-12: 

RDA for Vitamin B-12 1 mcg/ day for adults and elderly adults Pregnancy 1.5ug/day Lactation 1.5 ug /day Children 0.2 ug /day B-12 stored in the liver 11/25/2011 Dr.N.B.Reddy CMCH & RC

Who is at Risk For Deficiency?: 

Who is at Risk For Deficiency? Vegetarians Breastfed infants of vegan moms Elderly Individuals with AIDS or HIV 11/25/2011 Dr.N.B.Reddy CMCH & RC

Deficiency of Vitamin B-12: 

Deficiency of Vitamin B-12 Pernicious anemia Never degeneration, weakness Tingling/numbness in the extremities (parasthesia) Paralysis and death Looks like folate deficiency Usually due to decreased absorption ability Achlorhydria especially in elderly Injection of B-12 needed Takes ~20 years on a deficient diet to see nerve destruction 11/25/2011 Dr.N.B.Reddy CMCH & RC

Vitamin C: 

Vitamin C Ascorbic acid (reduced form), dehydroascorbic acid (oxidized form) Synthesized by most animals (not by human) Absorbed by a specific energy dependant transport system Passive transport if intake is high Decrease absorption with high intakes Excess excreted 11/25/2011 Dr.N.B.Reddy CMCH & RC

Food Sources of Vitamin C: 

Food Sources of Vitamin C Citrus fruits Potatoes Green peppers Cauliflower Broccoli Strawberries Romaine lettuce Spinach Easily lost through cooking Sensitive to heat Sensitive to iron, copper, oxygen 11/25/2011 Dr.N.B.Reddy CMCH & RC

Functions of Vitamin C: 

Functions of Vitamin C Reducing agent (antioxidant) Iron absorption Synthesis of carnitine, tryptophan to serotonin, thyroxine, cortiscosteroids, aldosterone, cholesterol to bile acids Immune functions Cancer prevention? Collagen synthesis 11/25/2011 Dr.N.B.Reddy CMCH & RC

Collagen Synthesis (Fig. 10-12) : 

Collagen Synthesis (Fig. 10-12) 11/25/2011 Dr.N.B.Reddy CMCH & RC

Antioxidant: 

Antioxidant Can donate and accept hydrogen atoms readily Water-soluble intracellular and extracellular antioxidant Must be constantly enzymatically regenerated Needs are higher for smokers 11/25/2011 Dr.N.B.Reddy CMCH & RC

RDA for Vitamin C: 

RDA for Vitamin C 90 mg/day for male adults 75 mg/day for female adults +35 mg/day for smokers Average intake ~72 mg/day Fairly nontoxic (at <1 gm) Upper Level is 2 g/day Warning to people with hemochromatosis, oxalate kidney stones 11/25/2011 Dr.N.B.Reddy CMCH & RC

Deficiency of Vitamin C: 

Deficiency of Vitamin C 11/25/2011 Dr.N.B.Reddy CMCH & RC Scurvy Deficient for 20-40 days Fatigue, pinpoint hemorrhages Bleeding gums and joints. Hemorrhages Associated with poverty Rebound scurvy immediate halt to excess vitamin C supplements Who is at risk? Infants, elderly men Alcoholics, smokers

Slide 60: 

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