Presentation Overview Explore chemistry, functions, deficiency, adequacy, toxicity, and food sources of the water soluble vitamins: thiamin, riboflavin, niacin, B6, B12, folate, vitamin C, panthothenic acid, biotin, and choline.
Thiamin: B 1 Chemistry & Functions Enzyme cofactor in energy metabolism: Carbohydrate & BCAA. –B 1 functions as the active group of thiamin pyrophosphate (TPP). Supports normal appetite & nervous system function.
Thiamin: B 1 Deficiency & Toxicity Deficiency (<66% of DRI) Approx. <0.8 mg/day Adequacy DRI: 1.1-1.2 mg/day RDI: 1.5 mg Beriberi (wet and dry) Cardio-Vascular: Heart rhythm changes Central Nervous System: Mental changes, confusion, amnesia, disturbed eye movement GI System: Nausea, anorexia Neuro-Muscular: Muscle weakness, tingling hands and feet peripheral paralysis, decreased ability to coordinate motor movement, disturbed gait Other: Edema, exhaustion, weight loss Normal energy (Glucose & BCAA) metabolism. Normal appetite and nervous system functioning. DRI is based upon 0.5 mg B 1 per 1,000 Calories Adult DRI values Toxicity is poorly documented in humans (UL is Not Established)
Thiamin: B 1 Food Sources Pork Whole grains Enriched bread and cereal products It is added back by law to processed grains
Riboflavin: B 2 Chemistry & Functions Enzyme cofactor in energy metabolism: fatty acid oxidation. –B 2 functions as the active group of two coenzymes flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD).
Riboflavin: B 2 Deficiency & Toxicity Deficiency (<66% of DRI) Approx. <0.85 mg/day Adequacy DRI: 1.1-1.3 mg/day RDI: 1.7 mg Ariboflavinosis Bone & tooth: Halts growth GI System: Sore and swollen throat, swollen magenta colored tongue, cracking at the corners of the mouth Skin: Dandruff Normal fatty acid metabolism Toxicity is poorly documented in humans (UL is Not Established) DRI is based upon 0.6 mg B 2 per 1,000 Calories Adult DRI values
It is added back by law into processed grains Riboflavin: B 2 Food Sources Milk products Organ meats Whole and enriched grains and products such as bread, cereal, and pasta
Niacin: B 3 Chemistry & Functions Enzyme cofactor in energy metabolism: amino acids, fatty acids, and glucose –A part of nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP). –Supports steroid synthesis, health of the skin, nervous system, and digestive system. 1 niacin equivalent (NE) = 1 mg nicotinic acid. 60 mg tryptophan can produce 1 NE.
Niacin: B 3 Deficiency & Toxicity Deficiency (<66% of DRI) Approx. <9-11 mg/day Adequacy DRI: 14-16 mg/day RDI: 20 mg Toxicity (>UL) >35 mg/day Pellegra Central Nervous System: Depression, apathy, headache, dementia (including memory loss). GI System: Bright red tongue, diarrhea (GI disturbances of vomiting, diarrhea, and constipation) Skin: Dermatitis Other: Fatigue Normal energy metabolism & steroid synthesis. Not from food but rather nicotinic acid supplements Cardio-Vascular: Violent flushing reaction from vasodilation Central Nervous System: Blurred vision GI System: Nausea, vomiting, liver toxicity DRI is based upon 6.6 mg B 3 per 1,000 Calories Adult deficient, adequate, toxic values
Meats, fish, poultry Whole & enriched grains & products Bread, cereal, & pasta Dairy products & legumes are good sources of tryptophan It is added back by law into processed grains Niacin: B 3 Food Sources
Vitamin B 6 Chemistry & Functions B 6 forms (PN, PL, PM, PNP, PLP, PMP) are coenzymes in the metabolism of amino acids, glycogen, and some lipids. Interconversion of amino acids (AA) to carbohydrate or carbohydrate to nonessential AA. –Removal of N from AA: “deamination” & "transamination" Needed for heme synthesis & conversion of tryptophan to niacin.
Vitamin B 6 Deficiency & Toxicity Deficiency (<66% of DRI) Approx. <0.85 mg/day Adequacy DRI: 1.3 mg/day RDI: 2 mg Toxicity (>UL) >100 mg/day Cardio-Vascular: Microcytic anemia Central Nervous System: confusion, depression, epileptic convulsions Skin: Seborrheic (greasy) dermatitis Normal metabolism of amino acids, glycogen, and some lipids. Normal heme synthesis & conversion of tryptophan to niacin. Not from food but rather large supplement doses Neuro-Muscular: Nerve damage, sensory neuropathy, tingly to numb hands and feet Skin: Dermatological lesions DRI is based upon 0.016 mg of B 6 per gm pro consumed Adult deficient, adequate, toxic values
Vitamin B 12 Chemistry & Functions Cobalamin contains cobalt Required for nucleic acid, red blood cell & other new cell synthesis. Important for nerve cell maintenance. Cofactor in energy fatty acids & amino acids metabolism Conversion of homocysteine to methionine. Synergizes with folic acid.
Vitamin B 12 Interesting Facts Needs intrinsic factor (a protein produced in the stomach) and gastric acid. Is absorbed in the ileum. If the GI tract is not healthy, B 12 must be given by intramuscular injection. Nasal spray B 12 supplements are available. With high dietary intakes, the excess can be stored accumulatively in the liver.
Vitamin B 12 Deficiency & Toxicity Deficiency (<66% of DRI) Approx. <0.85 µg/day Adequacy DRI: 2.4 µg/day RDI: 6 µg/day Pernicious anemia. Macrocytic normochromic anemia, compounded with nerve damage. Central Nervous System: Loss of concentration, memory loss, disorientation, dementia, visual disturbances GI System: Impaired bowel (increased gas production & constipation), sore tongue & loss of appetite Neuro-Muscular: Nerve damage, gait disturbances, tingling & numbness in the hands & feet Other: Insomnia, impotency, reduced bladder control Normal synthesis of nucleic acids and new cells, nerve cell maintenance, fatty acid and amino acid metabolism, and homocysteine catabolism. Normal synergy with folate Adult deficient, adequate values Toxicity is poorly documented in humans (UL is Not Established)
Vitamin B 12 Food Sources Animal food sources: eggs, milk, cheese, meats. Since it is commonly found in animal products, vegans need to supplement this nutrient.
Vitamin C Chemistry & Functions Required for collagen synthesis needed in skin, bones, teeth, blood, epithelial tissue, tendons & ligaments. Cofactor for carnitine & neurotransmitter synthesis. Water soluble antioxidant Increases absorption of non-heme iron
Vitamin C Deficiency & Toxicity Deficiency (<66% of DRI) Approx. <50-60 mg/day Adequacy DRI: 75-90 mg/day RDI: 60 mg/day Toxicity (>UL) >2000 mg/day Scurvy Central Nervous System: Weakness, fatigue, depression GI System: Swollen red bleeding gums Skin: Follicular hyperkeratosis, petechia, easy bruising, impaired wound healing Other: Joint pain, edema, coiled hairs Normal collagen synthesis & connective tissue formation. Normal carnitine, neurotransmitter, and water soluble antioxidant function GI System: Gastrointestinal disturbances especially diarrhea Other: Increased risk for kidney stones and iron toxicity only in certain people Adult deficient, adequate, toxic values Smokers need +35 mg/day
Vitamin C Food Sources Citrus fruits, berries, kiwi, and melons Cabbage family vegetables, peppers, Vitamin C fortified foods
Pantothenic Acid Chemistry, Functions, & Food Sources Essential component in Coenzyme A which is involved in metabolism of fatty acids, cholesterol, steroid hormones, vitamins A and D, neurotransmitters, amino acids, & porphyrin & corrin rings.
Pantothenic Acid Deficiency & Toxicity Deficiency (<66% of DRI) Approx. <3.3 mg/day Adequacy DRI: 5 mg/day Central Nervous System: Fatigue, apathy, irritability, restlessness GI System: Nausea, vomiting, abdominal cramps Neuro-Musccular: Muscle cramps, impaired gait Other: Burning feet, sleep disturbances, hypoglycemia, and increased insulin sensitivity Normal coenzyme A activity & metabolism of fatty acid, cholesterol, steroid hormones, vitamins A and D, neurotransmitters, amino acids, and porphyrin and corrin rings Adult deficient, adequate values Toxicity is poorly documented in humans (UL is Not Established)
Pantothenic Acid in Foods Adult DRI: 5 mg/day Widely distributed in food, highest in high protein animal products, yeast, legumes, and whole grains
Biotin Chemistry, Functions, & Food Sources Coenzyme in carboxylation reactions in energy metabolism. Cell proliferation, gene silencing, & DNA repair. Widespread in foods, highest in high protein animal products, yeast, legumes, nuts, whole grains, & chocolate. Small amounts made by intestinal bacteria. Quantitative data unavailable for graphical analysis
Biotin Deficiency & Toxicity Deficiency (<66% of DRI) Approx. <3.3 mg/day Adequacy DRI: 30 µg/day Central Nervous System: Lethargy, depression, hallucinations, weakness, fatigue Neuro-Muscular: Muscle pain Skin: Scaly red rash around the eyes, nose and mouth Other: Conjunctivitis, hair loss Normal energy metabolism, cell proliferation, gene silencing, and DNA repair Adult deficient, adequate, toxic values Toxicity is poorly documented in humans (UL is Not Established)
Choline Chemistry & Functions Is a component of the neurotransmitter acetylcholine, thus plays a role in memory and muscle control. Is in the phospholipid, lecithin (phosphatidlycholine) which is needed to maintain cell membrane stability. Needed for lipid and cholesterol transport and metabolism, component of pulmonary surfactant Is in bile acids
Choline Deficiency & Toxicity Deficiency (<66% of DRI) Approx. <280-360 mg/day Adequacy DRI: 425-550 mg/day Toxicity (>UL) >3,500 mg/day GI System: Fatty liver and liver damage Normal acetylcholine, cell membrane stability, bile acids, lipid and cholesterol transport and metabolism, pulmonary surfactant Cardio-Vascular: Hypotension GI System: Altered liver function, increased salivation Other: Fishy body odor Adult deficient, adequate, toxic values
Choline Food Sources Egg yolk, soy beans, peanuts High protein animal products Quantitative data unavailable for graphical analysis
Summary The water soluble vitamins have specific functions. DRIs are established for all essential water soluble vitamins. Deficiency and toxicity sign and symptoms are established for most of these nutrients. References for this presentation are the same as those for this topic found in module 5 of the textbook