Vitamins Flashcards
A
- Retinol
- Deficiency: night blindness, alopecia, scaly skin
- Excess: arthralgias, cerebral edema, hepatic abnormalities, teratogenic (accutane)
- high doses can be used to treat measles and cancer
B1
- Thiamine
- Links many dehydrogenase rxns: pyruvate dehydrogenase, alpha-ketoglutarate dehydrogenase, branched-chain ketoacid dehydrogenase, transketolase
- Deficiency: ATP depletion, Wenicke-Korsakoff, seen in EtOH abuse. Dry beriberi (wasting of muscle). Wet beriberi (dilated cardiomyopathy).
B2
-Riboflavin
-Component of FAD and FMN, used as cofactor in redox rxns (FA oxidation, AA oxidation, Aerobic Metabolism)
-Needed for tryptophan to become Niacin
Deficiency: 2Cs… cheilosis and corneal vascularization
B3
-Niacin
-Derived from tryptophan, synthesis requires B2 and B6
-Lowers VLDL and raises LDL (not used clinically bc of SE)
-Deficiency: 3Ds… Diarrhea, Dementia, Dermatitis, also leads to Hartnup disease
Excess: Facial flushing, hyperglycemia, hyperuricemia
B5
- Pantothenate
- Essential component of coenzyme A (CoA factor for acyl transfers) and FA synthesis
- Deficiency: Dermatitis, enteritis, alopecia, adrenal insufficiency
B6
- Pyridoxine
- Helps breakdown glycogen
- Homocystein > (B6 + cystathione synthase) > cystathione > cystein
- Works with delta-aminolevulinic acid as the RDS of heme synthesis
- Deficiency: sideroblastic anemia (bc of iron excess), peripheral neuropathy, convulsions
B7
-Biotin
-Adds 1 C to substrate, works in following carboxylations rxns
pyruvate > oxaloacetate
acetyl-Coa > malonyl-CoA
proprionyl-Coa > methylmalonyl-CoA
Deficiency: (rare) dermatitis, alopecia, enteritis
B9
- Folic Acid
- Converted to THF
- Deficiency: macrocytic/megaloblastic anemia, hypersegmented neuts, glossitis, no neurological symps
- Most common deficiency in the US
B12
- Cobalamin
- Cofactor for homocysteine methyltransferase and methylmalonyl-CoA mutase
- Synthesized only by microorganisms
- Anti-IF abs = pernicious anemia
- Schilling test: radiolabeled B12, if
C
- Ascorbic Acid
- Facilitates Fe absorption by reducing it to Fe2+
- Necessary for hyroxylation of proline and lysine
- ” for beta-hydroxylase which turns dopamine > NE
- Scurvy: swollen gums, bruising, wounds don’t heal, corkscrew hair
D
- Increases absorption of Ca++ from gut and increases bone mineralization
- Rickets: bone pain and deformity (found in kids)
- Osteomalacia: thin, brittle bones in adults
- Hypocalcemia: tetany, arrhythmia, seizures
Vitamin E
- Antioxidant, protects RBCs
- Can enhance coagulating effects of Warfarin by inhibiting Vit K
- Deficiency: hemolytic anemia, acanthocytosis, muscle weakness, posterior column and spinocerebellar tract demyelination
Vitamin K
- Made by intestinal flora, not found in neonates
- Needed for blood clotting
Zinc
- Essential for activity of 100+ enzymes
- Delayed wound healing, decreased adult hair, dysgeusia, anosmia
