Vitamins Flashcards
Functions of Vitamin A
- Prosthetic group of visual pigments
- Nuclear modulator of gene expression
- differentiation of epithelial
VItamin A deficiency
- night blindness
- dedifferentiation = poor appetite, poor growth,
- xerophthalmia
Functions of Vitamin D
- maintain serum Ca & P concentrations
- increase intestinal absorption
- increase bone resorption
- increase renal reabsorption
Vitamin D deficiency
- Rickets in children
- Osteomalacia
Function of Vitamin E
- scavenger of free radicals and peroxyl radicals
- inhibition of platelet aggregation and increased vasodilation
Function of Vitamin K
-regulation of blood clotting protein synthesis; 7 vitamin K-dependent proteins involved in coagulation
Function of Thamin (B1)
- Coenzyme as TPP for aldehyde transfers
- Oxidative decarboxylation - pyruvate dehydrogenase
- Transketolase reactions in PPP
Thiamin Deficiency
- Dry beriberi
- Wet beriberi
- Cerebral beriberi
Dry beriberi
- peripheral neuropathy
- calf muscle tenderness
- bilateral wrist and ankle drop
- symmetric impairment of sensory, motor, and reflex functions
Wet beriberi
- also called cardiac beriberi
- edema
- tachycardia
- cardiomegaly
- CHF
Cerebral beriberi
- Wernicke’s enncephalopathy
- mental confusion
- 6th nerve paralysis & coma
Riboflavin (B2)
-redox enzyme (FAD & FMN) in energy yielding reactions in CAC and b-oxidation (electron carriers for the enzymes)
Riboflavin Deficiency
-sore throat, cheilosis, angular stomatitis, glossitis, seborrheic, dermatitis
Niacin
-Coenzymes (NAD & NADP) in redox reactions, ATP synthesis, ADP ribose transfer reactions
Niacin Deficiency
- Pellegra photosensitive dermatitis; symmetrical lesions on parts of body exposed to sun (except face)
- dermatitis, diarrhea, dementia, and death
Vitamin C (Ascorbic acid)
- Coenzyme in redox reactions
- Norepinepthrin and serotonin biosynthesis
- crosslinking of collagen
- non heme absorption
Vitamin C defiecincy
- scurvy
- defects in collagen formation
- a bunch of other stuff
Folic Acid
- Coenzyme for one-carbon (methyl group) transfer reactions
- purine and pyrimidine synthesis & methylation of reinsure RNA
Cobalamin (B12)
- non organic component - cobalt atom
- coenzyme for one carbon transfers (methionine synthase and methylmalonyl-coA mutase
Folic Acid Deficiency
- defective DNA/RNA synthesis
- megaloblastic anemia; nucleated RBC with dispersed chromatin
- symptoms similar to iron deficiency anemia
- hyperhomocysteinemia
Cobalamin Deficiency
- similar symptoms to folate deficiency
- pernicious anemia
- increased homocysteine
- defective DNA/RNA synthesis
