Vitamins Flashcards
Vit A
Retinol
- antioxidant, visual pigments, needed for differentiation of epithelial cells into specialized tissue, prevents squamous metaplasia
- Def = night blindness, dry/scaly skin, corneal degeneration, bitot spots, immunosuppression
- Used for cystic acne and APL
Vit B1
Thiamine
- TPP is cofactor for… ATP (alpha keto-glut dehydrogenase, transketolase, pyruvate dehydrogenase) and branched chain ketoacid dehydrogenase
- Def = impaired glucose breakdown –> dec ATP (brain and heart); unresponsive to dextrose so replace B1 b/f
Ber1Ber1 (dry - polyneuritis and muscle wasting v. wet - high output cardiac fail and edema)
Wernicke-Korsakoff - confusion + opthalmoplegia + ataxia
Vit B2
Riboflavin
- FAD (2 ATP for vit B2) and FMN
- Needed for succinate dehydrogenase in TCA
- Def = 2 C’s (cheliosis, corneal vascularization)
Vit B3
Niacin
- NAD+ and NADP+ (3 ATP)
- Made from trypotophan w/ B2 and B6
- Def = 3 D’s (dementia, diarrhea, dermatitis in broad collar area); pellagra
Vit B5
Pantothenic Acid
- CoA and FA synthase
- Def = dermatitis, enteritis, alopecia, adrenal insufficiency
Vit B6
Pyridoxine
-PLP is cofactor for … ALT/AST, decarboxylations, glycogen phosphorylase, synthesis of heme, niacin, histamine, serotonin, epi, NE, dopamine, GABA
Dec = convulsions, peripheral neuropathy, hyper-irritable, sideroblastic anemia
Vit B7
Biotin
-Carboxylations (add carbon group)
- Pyruvate –> OAA
- Acetyl CoA –> malonyl CoA
- propionyl CoA –> methylmalonyl CoA
Def = RARE but dermatitis, alopecia, enteritis (associated w/ raw eggs b/c white bind biotin)
Vit B9
Folate
- Converted –> THF for 1 methyl transfer and methylation
- DNA/ RNA synthesis
- Def = macrocytic anemia and hyper-segmented PMNs w/ normal methylmalonic acid and no neuro symptoms
Vit B12
Cobalamin
- Methionine synthase & methylmalonyl CoA mutase
- Def = macrocytic anemia and hyper-segmented PMNs w/ inc methlymalonic acid and homocysteine w/ abnormal myelin so dorsal columns and later tracts
Vit C
Ascorbic Acid
- Antioxidant, inc iron absorption by reducing it to Fe+2 state
- Also needed for hydroxylation in collagen synthesis (scurvy)
- Def = swollen gums, bruising, petechiae, hemarthosis, anemia, poor wound healing, corkscrew hair, weak immune system
Vit D
D2 - ergocalciferol (plants)
D3 - cholecalciferol (milk, skin)
- Inc absorption of Ca and phos in intestine
- Def = Rickets (bow legs), osteomalacia (bone pain and weakness in adults), hypocalcemic tetany
- Excess = inc Ca, loss of appetite, stupor
Vit E
Tocopherol/tocotrienol
- Antioxidant (protects RBCs and membranes from free radical damage)
- Def = neuro similar to B12 w/o megaloblastic anemia, inc methylmalonic acid or hyper-segmented PMNs
Vit K
Activated by epoxide reductase –> cofactor fo carboxylation of glutamic acid residues on clotting factors (2, 7, 9, 10, protein C and protein S)
Synthesized by intestinal flora (can be deficient in neonates and after long-term abx b/c dec intestinal flora)
Zinc
Def = delayed wound healing, hypogonadism, dec adult hair, ansomnia, acrodermatitis enteropathica
May also predispose to alcoholic cirrhosis
