TN Vitamins Flashcards
Organic compound that is required in the diet in small amounts for the maintenance of normal metabolic integrity
Vitamin
Organic compound that is required in the diet in small amounts for the maintenance of normal metabolic integrity
All vitamins conform to the definition above EXCEPT
Vitamin D (Skin synthesis)
Deficiency of this vitamin causes night blindness, xerophthalmia, keratinization of skin
Vit A
Vitamin involved in the maintenance of Calcium balance;
Enhances intestinal absorption of Ca2+ and metabolizes bone mineral;
Regulation of gene expression and cell differentiation
Vit D
Vitamin that acts as anti-oxidant esp in cell membranes;
roles in cell signaling;
Deficiency extremely rare but has neurologic dysfunction
Vit E
Vitamin that acts as a co-enzyme in formation of carboxy glutamate in enzymes of blood clotting and bone matrix
Vit K
Vitamin that acts as Co-enzyme in pyruvate and alpha keto-glutarate, branch chain acid dehydrogenase complex, transketolase, and regulates Cl channel in nerve conduction
Vit B1 Thiamine
Def of this vitamin causes peripheral nerve damage, heart failure (beri beri) or CNS lesions (Wenicke-Korsakoff synd)
B2 Riboflavin
Vitamin that acts as a coenzyme in transamination and decarboxylation of amino acids and glycogen phosphorylase; modulation of steroid hormone action
Pyridoxine B6
Vit that acts as co-enzyme in oxidation/reduction reactions (FAD and FMN);
Prosthetic group of falvoproteins, deficiency causes lesions in corner of mouth, lips and tongue, seborrheic dermatitis
B2 Riboflavin
Vit that acts as co-enzyme in oxidation/reduction reactions;
Functional part of NAD and NADP;
Role in intracellular Ca regulation and cell signaling
B3 Niacin
Def of this vitamin causes pellagra: (4Ds) Diarrhea Dermatitis Dementia Death
B3 Niacin
Vit acting as co enzyme in transfer of 1-carbon fragments and metabolism of folic acid;
deficiency causes Pernicious anemia (megaloblastic anemia with degeneration of spinal cord)
Vit B12 Cobalamin
Vitamin involved as co enzyme in transamination and decarboxylation of amino acids and glycogen phosphorylase
Modulation of steroid hormone action
Vit B6 Pyridoxine
Vit acting as co enzyme in transfer of 1 carbon fragments in form of tetra-hydro-folate
deficiency causes megalobastic anemia and Neural tube defects
Folate B9
Substance required for absorption of vit B12 in the terminal ileum
Intrinsic factor
Vit forming the functional part of CoA and acyl carrier protein involved in FA synthesis and metabolism
Pantothenic Acid B5
Def of this vitamin causes peripheral nerve damage
Nutritional melalgia
“Burning foot syndrome”
Vit B5 Pantothenic acid
Vit acting as coenzyme in carboxylation reactions in gluco-neo-genesis and FA synthesis; role in regulation of cell cycle
Biotin (biocytin)
Enzyme that require biotin
Acetyl Coa Carboxylase
Pyruvate Carboxylase
Propionyl CoA carboxylase
Methyl-crotonyl CoA carboxylase
Substance in egg white that decreases biotin absorption
Avidin
Vit functioning as Coenzyme in hydroxylation of proline and lysine in collagen synthesis;
anti-oxidant
enhances absorption of Iron
Vit C
Deficiency of this vitamin causes scurvy - impaired wound healing, loss of dental cement, subcutaneous hemorrhage
Vit C
Both def and excess of this vitamin interferes with Vit D function by virtue of altered RXR receptor dimerization
Vit A
Most important preventable cause of blindness
Vit A deficiency
Sequence of changes in vit A def
Earliest sign: LOSS of sensitivity to GREEN then Impairment to adapt to dim light then Night blindness
Toxicity from this vitamin causes
- increased CSF pressure–> headache, nausea, ataxia, and anorexia,
- The liver: hepatomegaly with histologic changes in hyperlipidemia
- Calcium homeostasis (thickening of the long bones, hypercalcemia, and calcification of soft tissues)
Skin: excessive dryness, desquamination and alopecia
Vitamin A
Major source of vit D
Skin synthesis
Precursor of Vit D synthesis in the Skin
7-dehydro-cholesterol
Vit D deficiency leads to what dse in children
Rickets
Vit D def leads to what disease in adults
Osteomalacia
Vit that is considered a hormone
Vit D
Main storage form of vit D
25-hydroxy-chole-calciferol
bound to
Vit D binding globulin
Steps in vit D hydroxylation
25 hydroxylation in liver
1 hydroxylation in the kidney
Principal funciton of vit D
Maintain serum calcium levels
Most active form of vitamin E
D alpha tocopherol
Excess of this vitamin causes contraction of blood vessels, high blood pressure and calcinosis
Vit D
Vit that does NOT have a precisely defined metabolic function
Vit E
3 compounds with biologic activity of Vit K
Phyllo-quinone - normal dietary source (green vegtables)
Mena-quinones - synthesized by intestinal bacteria
Mena-dione/Mena-diol diacetate - synthetic compounds that can be metabolized to Phylloquinone
Classic example of vit K antagonist
Warfarin
Bone calcium binding proteins taht are synthesized with the help of vit K
Osteo-calcin and
Bone matrix G1A protein
Thus warfarin causes skeletal deformities in fetus
Proteins involved in the coagulation system affected by vit K
Factors 2 7 9 10
Protein C & S
Thaimine def can be assessed with this test
RBC trans-ketolase activation
Vit with intense yellow color used as food additive
B2
Which vitamin is not strictly a vitamin because it can be synthesized from the body
B3
Amino acid precursor of niacin
Tryptophan
Diet pre-disposing to B3 deficiency
Corn Diet
Dse causing pellagra despite adequate intake of tryptophan and niacin
Hartnup and
Metastatic Hepatic Carcinoid syndrome
Vit used as a drug to treat hyperlipidemia, low LDL
Nicotinamide, B3
Common side effect of niacin or nicotinamide
Flushing
Vit used to prevent peripheral neuropathy but in excess also causes peripheral neuropathy
Pyridoxine
Vit found only in foods of animal origin
B12
Vit B12 binding protein secreted in the saliva
Cobalophilin
Vit B12-dependent enzymes (3)
Methyl-malonyl CoA Mutase
Leucine Amino-Mutase
Methionine Synthase
MCC of pernicious anemia
Failure of B12 absorption
Drug that inhibits di-hydro-folate reductase in humans, making it a good anti-cancer drug
Metho-trexate
Drug that inhibits dihydrofolate release in bacteria
Trimethoprim
Impairment of methionine synthase in vit B12 def results in the accumulation of methyl-tetra-hydro-folate, aka functional folate deficiency
Folate trap
Co factor for dopamine beta hydroxylase enzyme
Vitamin C
