Water Soluble Vitamins (week 6).docx

The B Vitamins  Do not provide energy o However, the absense of B vitamins would be a lack of energy o Coenzymes  They help enzymes release energy from proteins, carbs, and lipids o Essential to metabolism  Thiamin (B1) o Coenzyme TTP  Helps in energy metabolism  Occupies a spot on the membranes of nerve cells  Plays role in nerves and responding tissues o Recommendations based on role in enzyme activity  Needs are met if person is taking in enough energy from nutritious foods o Deficiency  Those who fail to eat enough food to meet energy needs  Alcoholics  Homeless people  Thiamin and Alcoholics o Energy is obtained from alcohol and not nutritious food o Alcohol impairs thiamin absorption o Alcohol enhances thiamins excretion in the urine  Causes thiamin deficiency in alcoholics  Wernicke’s syndrome  Disorientation  Staggering  Loss of short term memory  Beri Beri Disease  Originated when rice was polished and germ and bran were removed  Wet Beri Beri  Edema  Dry Beri Beri  Muscle wasting o Symptoms  Cardiac failure  Muscle weakness  Poor short term memory  Confusion  Weight loss  Enlarged heart  No symptoms for thiamin toxicity o Thiamin loss or destruction  During refining process  Long cooking destroys thiamin by heart  Leaches out in water when boiled  Preservation  Cook with little water  Cook or steam in short periods o Sources  Whole grain  Enriched grain products  Pork  Occurs in small quantities in nutritious foods  Absent from refined foods Riboflavin (B2)  Coenzyme in energy metabolism o Forms  Flavin FMN, FAD  Recommendations o Based on role as an enzyme o Most meet recommended amounts  Deficiency o Accompanies other vitamin deficiencies o Result of poor diet  Flavinosis  Inflammation of membranes in mouth, skin, eyes, GI tract  Sore throat  Skin lesions  Cracks in mouth  Cheilosis  Purple tongue  Glossitis o No toxicity symptoms  Riboflavin loss or destruction o Ultraviolet light o Radiation  Can handle heat  Sources o Milk and milk products make greatest contirubtion to diet o Liver o Whole grains or enriched grains o Dark green leafy vegetables Niacin  Nicotinic Acid, Nicotinamide o Nicotinic acid is converted to nicotinamide which is it’s form in the blood  Roles o Coenzymes used in energy metabolism  Reccomendations o Can be made in the body by amino acid o Tryptophan  1mg of niacin is made from 60mg of tryptophan  Deficiency o Diarrhea, abdominal pain, vomiting, glossitis, depression, fatigue, loss of memory, rashes on area exposed to sunlight o Pallegra  4 D’s  Diarrhea, dermatitis, dementia, death  Low protein diet  Corn has amino acid which interferes in conversion of tryptophan to niacin  70% niacin in corn is bound to complex carbs and proteins so it will not be absorbed  Lead to the discovery that disease can be caused from a lack of something in the diet and not something infectious  Toxicity o None from foods o Niacin flush  Large doses of supplements o Nicotinic acid has been used to lower LDL cholesterol o Average diet contains enough niacin  Niacin loss o Can leach into water  Can withstand heat and cooking time  Sources o Milk, eggs, meat, fish, whole grains,  Protein Biotin  Coenzyme in energy metabolism  Gluconeogenesis o Fatty acid synthesis and breakdown of fatty acids and amino acids  Recommendations o Needed in small amounts o AI is 30 micrograms per day  Deficiency o Deficiency is rare o Can occur with egg whites  Contain avidin that binds to biotin and prevents absorption  Symptoms o Skin rash, hair loss, neurological impairment, lethargy  Toxicity o None reported  Sources o Widespread in foods o Liver, egg yolks, soybeans, whole grains o Can be produced in the GI tract Pantothenic Acid  Part of chemical structure in coenzyme A  Used in energy metabolism o Involved in making of lipids, neuotransmitters, and hormones and hemo globin  Recommendations are based on daily losses and adequate intake  Deficiency o Rare o Symptoms are a general failure of all body systems  Fatigue, GI stress, neurological problems  No toxicity level  Destruction o Canning, freezing, refining  Sources o Chicken, potatoes, tomatoes, fruits vegetables, eggs, oats, liver Vitamin B6  Pyridoxine, Pyridoxal, Pyridoxamine o Part of coenzyme PLP and PMP o Amino acid and fatty acid metabolism  Convert tryptophan to niacin  Helps make red blood cells  Unlike other water soluble vitamins B6 is stored in muscle tissue  Deficiency o Decreased synthesis of neurotransmitters o Abnormal compounds during metabolism accumulate in the brain  Confusion and depression  Abnormal brainwave patterns and convulsions o Alcohol contributes to B6 destruction and excretion  Alcohol break down can break PLP coenzyme from its other enzymes  Gets broken down and excreted o Drugs can cause deficiency  INH can bind and inactivate B6  Toxicity o Depression, fatigue, irritability, headaches, nerve damage, skin lesions o Neurological damage for more than 2g daily  Destruction o Can be destroyed by heat  Sources o Meat, fish, poultry, starchy vegetables, legumes, non citrus fruits, liver, soy o Bioavailability in plant sources is decreased Folate  Folacin, Folic Acid, PGA o Involved in synthesis of DNA o Formation of new cells  Absorption o Polyglutamate  Bound folate found in food  Combined with amino acids o Intestine prefers free folate  Monoglutamate  Polyglutamate is hydrolyzed to monoglutamate by intestinal enzymes  Methyl group gets attached to monoglutamate and gets sent to the liver and other body cells  Inside cells folate is inactive because of methyl group  Methyl group is removed by an enzyme that requires B12 to allow folate to become available for activation o Absorption Recap  Problem:  Foods deliver folate mainly in bound form (combined with a string of glutamates - polyglutamte)  Intestine absorbs folate with only one glutamate (monoglutamate)  Solution  Intestinal enzymes hydrolyze polyglutamate to monoglutamate and several glutamates  Next a methyl group is added.  The monoglutamate with the methyl group is transported to the liver and other body cells  Problem  For folate to function as a coenzyme, methyl group must be removed  Solution  B12 plays a role in removing and keeping methyl group and activating folate  Losses o Folate can be lost in GI tract o If GI tract is damaged then folate is lost  Alcohol abuse  Renewal of GI tract is impaired with folate deficiency o Folate is reabsorbed repeatedly because it released in the GI tract with bile  Recommendations o Bioavailability  50-100%  50 from food, 100, from supplment  Folate from food is given full credit = 1  Folate supplements more credit = 1.7  100 micrograms from food and 100 micrograms from supplements  =100 + (100x1.7)  =100+ 170  =270 micrograms of DFE (Dietary Folate Calculations o 400 micrograms for adults  More for pregnant women, 600 micrograms  Folate is critical in reducing neural tube defects  Brain and spinal cord are developed and defects can occur early in pregnancy  Neural tube defects have been decreasing with added folic acid o Addition of folic acid to white flour and pasta products in Canada  Fortified foods add 100 micrograms – 200 to the diet  Deficiency o Impairs cell division and protein synthesis  Problems with replacement of red blood cells and GI tract cells  Leads to anemia, GI tract deteri