Chapter 13 Water Soluble Vitamin Flashcards
Overview of Water-Soluble Vitamins
Storage in bodily tissues is minimal --Risk of toxicity less than fat-soluble --Easily destroyed during cooking Co-Enzymes --Utilized in energy conversion --Activated by digestion --50-90% of B vitamins are absorbed –Marginal deficiencys more common (college students) –Enrichment Act (adding nutrients back into food prevents wide spread deficiecies)
Vitamin B1– Thiamin
First one discovered
–Very unstable in alkali or basic solution
Functions
–Co-enzyme: Thiamin Pyrophosphate (TPP)
–TPP involved in 2 energy production reactions
Conversion of pyruvate to acetyl CoA
• Required for Carbohydrate and branched chain amino acid reactions
Thiamin Deficiency
Beriberi “I can’t, I can’t” –Feeding polished rice; polished = remove bran & germ –Neuritis (inflamed nerves in legs) Mental depression, Anorexia; loss of appetite, Constipation, Peripheral Neuropathy, Neuro/muscular pain, Congestive heart failure Wernicke-Krsakoff -Thiamin deficiency in alcoholics -Disorientation -Loss of short term memory --Jerky eye movements --Staggering gate
*OH blocks the TTP from enter the blood stream
Vitamin B2- Riboflavin
Second B vitamin to be discovered (B2)
Chemistry and Properties
–Stable to basic solution & heat
–Unstable in Sunlight (UV)
Riboflavin (toxicity, deficiency)
Nontoxic: no UL
Deficiency
–Ariboflavinsis
–Cheilosis – dry cracks at sides of mouth; dry around nose
–Glossitis – inflamed tongue; magenta tongue (purple)
Riboflavin (Function)
Energy Metabolism –Co-enzymes: flavin mononucleotide (FMN) flavin adenine dinucleotide (FAD) •Aids in breakdown of fat •Antioxidant function
Vitamin B3- Niacin
Chemistry and Properties --Humans can produce niacin 2 forms found in diet –Nicotinic Acid: Body easily converts NA to nicotinamide –Nicotinamide: the form the body uses --Very stable and hard to breakdown
Niacin (Functions)
Functions
- -Co-Enzyme of NAD+ and NADPH needed for >20 metabolic pathways
- -Required for catabolism of carbohydrate, fat and protein
- -Required for synthesis of fat
- -Required in at least 200 reactions
Niacin (deficiency)
Deficiency –Pellagra – “rough skin” –Dry, dark, leathery skin on exposed parts of body –Symptoms - 4 D’s Dementia, Dermatitis, Diarrhea and Death –Pharmacological use Nicotinic Acid –lower LDL –increase HDL
Niacin (toxicity)
Toxicity
•Impossible to get too much from diet
Prescription of niacin available in form of nicotinic acid
–Rx = 3000 mg per/day to lower serum cholesterol
–Can cause symptoms of Diabetes, Liver disorders, Vasodilation or “Niacin Flush
Vitamin B5: Pantothenic Acid
Present everywhere Chemistry and Properties --Acetyl CoA can be produced if pantothenic acid is present Absorption --Through GI tract --Excess is excreted Function --Integral in CoA metabolism -Deficiency, Toxicity – NONE
vitamin B7: Biotin (functions)
Function --Participates in Carboxylation –Adding a carboxyl (-COOH) to an existing Carbon chain First step in: –Gluconeogenesis –Lipogenesis –NEAA synthesis
Biotin (deficiency & Toxicity)
Deficiency Symptoms –Depression –Lethargy –Hallucinations –Facial rash Toxicity •None reported
Vitamin C - Ascorbic acid
Background --All animals can synthesize vitamin C from glucose -Except Humans and guinea pigs Chemistry and Properties --6 C compound that has hydroxyl (OH) groups --Most unstable nutrient known Destroyed by: –Air –Light –Basic solution –Exposure Vitamin C lost in food processing
Vitamin C (Functions)
Functions --Collagen Sunthesis --Synthesis of other vital compounds • Anti-oxidant activity • Iron absorption • Immune function
