FNN Week 8 Intro to B Vitamins.pdf

Vitamin Folate/Folic Acid Vitamin B12 Thiamin Riboflavin Niacin Vitamin B6 Pantothenic Acid Choline Other Names Food folate/ pharmaceutical form Cobalamin Vitamin B1 Vitamin B2 Niacinamide 6 related compounds Vitamin B5 Solubility Water soluble B vitamin Water soluble Water solub...

Vitamin Folate/Folic Acid Vitamin B12 Thiamin Riboflavin Niacin Vitamin B6 Pantothenic Acid Choline Other Names Food folate/ pharmaceutical form Cobalamin Vitamin B1 Vitamin B2 Niacinamide 6 related compounds Vitamin B5 Solubility Water soluble B vitamin Water soluble Water soluble Water soluble Water soluble Water soluble Water soluble Both water soluble forms (choline) and lipid soluble forms (phosphatidylc holine) Units -Dietary Folate Equivalent (DFE) -1 DFE = 1 mcg folate = 0.6 mcg folic acid with foods or 0.5 mcg without food Functions -Coenzyme in nucleic acid metabolism (THF) -Homocysteine breakdown -Blood volume expansion and tissue growth during pregnancy -Coenzyme in amino acid and glycogen metabolism, serotonin (neurotransmit ter) and heme synthesis -Helps convert tryptophan to niacin -CoA synthesis, amino acid, steroid hormone, vitamin A, vitamin D, neurotransmitter synthesis -Hemoglobin synthesis -Required for cell membrane integrity, lipid transport and metabolism, brain development (neurotransmitt ers) -Body can synthesize but -Niacin Equivalents (NE) -60 mg tryptophan = 1 mg niacin = 1 NE -Enzyme cofactor in DNA/RNA synthesis, fatty acid metabolism, methylation reactions -Bone cell metabolism, activation of folate, blood -Enzyme cofactor in energy metabolism -Neurotransmi tter production -Enzyme cofactor in redox reactions (FMN, FAD) -Coenzyme in redox reactions (NADP, NAD) -Fatty acid synthesis, calcium mobilization, DNA repair, energy metabolism formation, nerve function -Roles in cognitive abilities, immune response, steroid hormone actions Absorption -Active transport -Passive diffusion -Delivered to cells where its trapped as inactive form (activated by vitB12) -Protein bound in blood -Stomach acid breaks down vitB12 and parietal cells release IF -Small intestine in the last 60 cm of ileum absorbed via active transport, some passive diffusion if not bound to IF Excretion -Urine -Reabsorbed in kidneys -Reabsorbed in bile -Some fecal loss -50% stored in Urine liver -Reabsorbed in bile -Some fecal loss -Some loss through skin -Low concentrations carrier mediated transport in jejunum and ileum -High concentrations passive diffusion -Absorption drops at intakes about 5 mg -FMN and FAD in food -Stomach frees FMN and FAD -Small intensive absorbs and metabolizes to riboflavin -Low intake active transport -High intake passive diffusion -Low concentrations facilitated transport -High concentrations passive diffusion -NAD converted and absorbed in intestines and liver -Passive diffusion in small intestine -Can be bound to proteins Excess through -Urine urine -Stored in muscle not enough to meet needs -Low concentration active transport small intestine -High concentrations passive diffusion small intestine Excess through urine -Water soluble absorbed via portal circulation -Lipid soluble via lymph to thoracic duct Primary Deficiency -Low plasma folate -Reduced red blood cell concentration and rise in homocysteine -Megaloblastic cells -Mean cell volume (MCV) increases, macrocytic anemia develops -Unlikely in healthy adults -Among vegans -Rare because body can synthesize from tryptophan -Sometimes seen with alcoholism or inhibitors of tryptophan -Corn or maize-based diets Not primary Secondary Deficiency -Associated with vitB12 deficiency -Alcoholism interferes with absorption -Drug interactions -Pernicious anemia causes loss of parietal cells (release IF) -Pancreatic insufficiency -Older adults -Smoking -Malabsorption syndromes -Malabsorption conditions -Alcoholism -Diseases involving abnormal tryptophan metabolism -Chemotherapy In pantothenic free diets, people taking PA antagonist drugs Symptoms -Develops -Macrocytic gradually but anemia (large harmful blood cells) -Gradual onset anemia -Dermatitis Depression, -Gastro-intestin confusion, al symptoms dermatitis, convulsion Irritability, gastro-intestinal problems, dermatitis -Anorexia, apathy, memory loss, confusion, irritability, Sore throat, glossitis, dermatitis, anemia, -Results in liver dysfunction (lack of lipid form) -Vulnerable groups to choline deficiency is growing infants, pregnant and lactating women and those with liver disease -Weakness, fatigue, headache, impaired protein synthesis Related Diseases -Peripheral neuropathy, paralysis Neural Tube Defects (NTD) in pregnancy Food Sources -All foods -Dark leafy greens, brussel sprouts, asparagus -Meat, fish, poultry, fortified foods, bacterial synthesis, animal foods -Not in plant based foods unless exposed to bacteria or fortified muscle weakness, heart failure, neuropathy -Cardiac arrest in infants -Edema, muscle wasting, peripheral neuropathy magenta tongue -Central nervous symptoms Wernicke-Kors akoff Syndrome (WKS) is a neurodegener ative disorder -Ariboflavinosis Pellagra is a -Cheilosis and skin condition angular stomatitis is formation of fissures on mouth -Plant and animal foods -Excellent sources are yeast, pork, legumes, wheat germ -Most plant and animal foods -Excellent source is milk products -Protein-rich foods -Milk, eggs are high in tryptophan not niacin -Fortification/en richment for grains -Found in meat, fish, poultry -Fortified cereal In almost all -Widely plant and animal available in foods plant and animal foods mostly in the form phosphatidylch oline -Eggs -Lecithin in process foods Loss from cooking -50-100% oxidized -pH > 8 -0-85% oxidized -Irradiation Inhibitors -Heat resistant -Will leach into cooking water -Large loss in milling of grain Food processing results in losses between 10-50% Corn or maize unless treated with lime or alkali Excess alcohol destroys vitB6 coenzyme 95% -30% meats and cereal grains -Highly available as free niacin in fortified foods 75% from food 50% of dietary and 100% of crystalline PA Unknown No known toxicity -No known toxicity from diet -From supplements causes vasodilatory effects and liver damage -No known effect from food -From supplements causes neuropathy of the extremities, permanent -Unlikely from foods -From supplements can cause fishy body odor, sweating, salivation, reduced growth rate, Anti-thiamin factors (ATF) limits availability of thiamin in foods Bioavailability -50% folate -100% folic acid -85% folic acid with food Toxicity -Negatively affected by UV lite and irradiation -Heat stable -From folic acid supplements -Neurological effects -9% from liver -60% from chicken No known toxicity -40-75% loss in grain refinement -Cooking destroys up to 50% in meat and up to 80% in vegetables No known toxicity nerve damage, skin lesions RDA Adults -400 mcg/day -240 mcg/day folic acid with food -200 mcg/day folic acid without food -600 mcg/day pregnancy 2.4 mcg/day -Men 1.2 mg/day -Women 1.1 mg/day -Men 1.3 mg/day -Women 1.1 mg/day -Men 16 mg/day -Women 14 mg/day 1.3 mg/day UL Adults 1000 mcg/day fortified foods/ supplements No UL No UL No UL 35 mg/day OTC supplements unless under medical supervision 100 mg/day AI Adults hypotension, hepatotoxicity No UL 3.5 g/day 5 mg/day -Men 550 mg/day -Women 425 mg/day