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
Vitamin C (Deficiency)
Deficiency Scurvy: bleed, skin blistering –Collagen molecules not maintained –Not common Rebound Scurvy –Found in babies whose mothers had excessive vitamin C intake during pregnancy • Movement is painful for infant • Need increased vitamin C and the need to be weaned
Vitamin C (toxicity)
Increased risk
– Diarrhea
– Kidney stones
– Cramping
Vitamin B6: Pyridoixine
3 forms – Pyridoxol (plant foods) – Pyridoxal (animal foods) – Pyridoxamine (animal foods) UV light unstable – sunlight inactivates Dry heat will also inactivate
Vitamin B6 (Functions)
Functions --Coenzyme for over 100 metabolic reactions Metabolism –PLP coenzyme involved in amino acid metabolism – Transamination – Deamination – Converts tryptophan to niacin Synthesis of compounds – Neurotransmitters, vitamins
Vitamin B6 (Deficiency)
Absorption is negatively impacted by Oral Contraceptives
–Can result from altered tryptophan metabolism
–Inadequate B6 disrupts Red Blood Cell synthesisand their O2 binding ability
–Microcytic hypochromic anemia (small red bllod cells that dont carried enough O2)
Vitamin B6 (Toxicity)
Can result from diet or Rx Neuromuscular dysfunction (painful and irreversible)
Vitamin B12: Cobalamin
Chemistry --Central atom cobalt Absorption --B12 is considered an Extrinsic factor –Needs to bind to intrinsic factor • Intrinsic factor (parietal cell) – Parietal cells synthesize HCl in stomach • About 50% of B12 is absorbed • 1/3 of adults >60 yrs lose some parietal cell function
Vitamin B12 (Function)
2 major functions –Red blood cell synthesis • Transforms folate into active form • Folate is needed for DNA and RBC synthesis –Nerve functioning & CNS integrity • Maintenance of the myelin sheaths • 3-5 year supply in liver
Vitamin B12 (Deficiency and Toxicity)
Deficiency Conditions
–Pernicious Anemia: specifically associated with B12 deficiency (caused by loss of gastric parietal cells)
–Macrocytic Anemiadeficit in B12 and folic acid
Causes
–If eat animal products but lack intrinsic factor
–Intake
• Treatment - B12 injections
• Vegans need supplementation
Toxicity: None
Vitamin B9- Folate
• Folic Acid or Folate Function • DNA synthesis • Cell division • Amino acid metabolism • Neurotransmitter synthesis • Conjunction with B6 & B12 & RBC synthesis
Folate (deficiency and toxicity)
Deficiency
–Can cause RBC synthesis abnormality
–Megoblastic Anemia large, puffy, purple
–RBC precursors can not divide normally become large, frail and immature
Toxicity: Rare
Choline
Functions: works in conjugation with the below
–Phospholipids, lipoproteins, cell membranes
Deficiency: Rare
