5/25 Flashcards
Vitamin C
Water soluble antioxidant and can allow for reduction of substrates
- Necessary for ER hydroxylation of proline and lysine which allow proper collagen formation in ECF
- Keeps Fe in the Fe2+ reduced state
- Necessary for dopamine decarboxylase which catalyzes conversion of Dopamine to NE
- Defency leads to scurvy with poor wound healing and curved hairs
- Anemia is also commonly seen
- Too much vitamin C can put patient at risk for iron overload because of increased GI absorption
Vitamin D
Lipid soluble transcription factor for GI Ca and P transfer proteins (calbindin)
- Synthesized from cholesterol in the skin (basal and spinosum) from UVB light (UVA is longer wavelength and lower energy) converted to 25 in liver and 1,25 in kidney
- D2 ergocalciferol from plants, D3 cholecalciferol from animals and sun
- Deficency lead to rickets in kids and osteomalacia in adults, characterized by osteoid matrix that is unmineralized
- Supplement in dark skinned individuasl
- Elevated levels are seen in sarcoidosis and can lead to hypercalcemia (stones, moans, groans)
Vitamin E
Lipid membrane antioidant
- Protects RBC membranes, deficency leads to acanthosis
- Also deficency leads to subacute combined degeneration (Loss of spinocerebellar, corticospinal, and dorsal columns)
Vitamin K
Gamma carboxylation of glutamate residues on clotting factorss
- Synthesized by gut flora, deficency in neonates and long term antibiotics
- Give prophylactice vitamin K to nweborns
- Will have elevated Pt and PTT otherwise. Bleeding time is normal
Zinc
Cofactor in a number of enzymes including DNA binding zinc fingers.
-Decrease leads to hypogonadism, decreased hair, increased risk of cirrhosis, gustartory and olfactory problems, delayed wound healing
Ethanol Metabolism
Alchols are metabolized by alcohol dehydrogenase to acetylaldehyde in the liver. (Zero order kindetics (also aspirin and phenytoin)
- Acetylaldehyde is converted to acetate by acetylaldehyde dehydrogenase
- Both reaction require NAD and generate NADH leading to an elevated NADH/NAD ratio
Fomepizole
inhibitis alcohol dehydrogenase and prevents conversion to acetyladlehyde
- used in methanol to prevent formic acid
- ethylene glycol to prevent oxlic acid formation
Disulfaram
- Inhibits acetylaldehyde dehydrogenase and prevents coversion to aceteate
- Elevations in acetlyaldehyd result in feeling of sickness and hangover
- Metronidazole
- Sulfonylureas
- Cephalosporins
- Grizeofulvin
Effects of elevated NADH
- Requires pyruvate to lactate conversion to increase and stops conversion of OAA to Malate
- Accumulation of Malate and Lactate
- Results in an inability to peform GNG and increased FA synthesis (Malate makes NADPH)
- Results in elevated fat production and fatty liver
- Also rseults in acidosis from lactate, ketones
- Hypoglycemia and hyperlipidemia
Kwashiokor
Protein malnutrition
- All proteins can’t be made by liver
- Edema because of deacreased oncotic pressure
- Fatty liver from impaired lipoprotein synthesis
- Anemia is also present
Marasmus
-Total calorie malnutrition results in severe wasting
