vitamins 3 Flashcards Preview

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Flashcards in vitamins 3 Deck (12):

function of vitamin C

antioxidant, faciliates iron absorption by reducing it to Fe2+ state. needed for hydroxylation of proline and lysine in collagen synthesis. needed for dopamin beta hydroxylase, which converts DA to NE
aka ascorbic acid


vitamin C deficienct

scurvy: swollen gums, bruising, hemarthrosis, anemia, poor wound healing, perifollicular and subperiosteal hemorrhaces, corkscrew hair, weak immune system


Vitamin C excess

nausea, vomiting, diarrhea, fatigue, calcium oxalate nephrolithiasis. incr. rsk of iron toxicity in ppl with predisposition


vitamin D forms

D2 from plants, D3 from milk and sun. 25-OH D3 stored. 1,25 (OH)2 D3 is the active form


function of vitamin D

incr. intestinal absorption of calcium and phosphate, incr. bone mineralization


deficiency of vitamin D

rickets in kids (bone pain + deformity), osteomalacia in adults. hypocalcemic tetany. breastfed infants should receive oral vitamin D. deficiency exacerbated by low sun exposure, dark skin, prematurity


Vitamin D excess

hypercalcemia, hypercalciuria, loss of appetite, stupor. seen in sarcoid because of incr. activation of vitamin D by epithelial macrophages


Vitamin E: function, clinical consideration

antioxidant that protects erythrocytes from free radical damage. can enhance anti-coagulant function of warfarin


deficiency in vitamin E

hemolytic anemia, acanthocytosis (RBC with spiked cell membrane), muscle weakness, posterior column and spinocerebellar tract demyelination. may look like B12 defieicny, but won't have megaloblastic anemia, hypersegmented PMNs, or incr. serum methylmalonic acid levels


vitamin K function

cofactor for gama-carboxylation of glutamic acid residues on proteins needed for blood clotting. synthesized by intestinal flora. needed for activation of clotting factors II, VII, IX, X, and proteins C and S. Warfarin is a vitamin K antagonis


vitamin K deficiency

neonatal hemorrhage with incr. PT and PTT but normal bleeding time. neonates can't synthesize vitamin K. can also occur after broad spectrum antibiotics. vitamin K isn't in breast milk, so infants are given vitamin K injections at birth.


zinc deficiency

delayed wound healing, hypogonadism, decr. adult hair, dysgeusia, anosmia, acrodermatitis enteropathica (metablic disorder where you can't absorb zinc. causes periorificial and limb dermatitis, alopecia, and diarrhea). may predispose to alcoholic cirrhosis.