Fat Soluble Vitamins (and C, for some reason) Flashcards
2 Forms of Vitamin D and 2 Conversions
D2 - ergocalciferol ingested from plants
D3 - cholecalciferol from sun (& milk)
To 25-OH in liver via 25-hydroxylase and 1,25-(OH)2 (calcitriol) from 1 alpha hydroxylase in kidney
Disease Causing Excess Vitamin D
Granulomatous disease - sarcoidosis. Increased activation of Vit D by epithelioid macrophages
3 Functions of Vitamin A
Antioxidant
Constituent of visual pigments
Differentiation of epithelial cells into specialized tissues (especially mucus secreting cells)
4 Conditions Vitamin A Can Treat
Wrinkles - topical
Acne - topical or oral - Isotretinoin (Accutane) (super teratogenic so requires pregnancy test)
Measles
AML subtype M3
Vitamin A Acute, Chronic, and Other Toxicity
Acute - nausea/vomiting/vertigo/blurred vision
Chronic - alopecia/dry skin/scaliness/hepatic enlargement, arthralgias, pseudotumor cerebri
Teratogenic - need neg pregnancy test and contraception before isotretinoin prescribed
Vitamin E (alpha tocopherol) Function, Deficiency, and Disease they do NOT help
Antioxidant - protects RBCs and membranes from free rads
HA, posterior column and spinocerebellar tract demyelination so ataxia and peripheral neuropathy (presentation similar to B12 but without megaloblastic anemia or hypersegmented nphils)
Do NOT decrease risk of AD
Vitamin K Function and which ones important for
Cofactor for gamme-carboxylation (posttrans modification) of coagulation factors, synthesized by intestinal flora
Necessary for Proteins C and S, and factors II, VII, IX, and X
Vitamin K Deficiency
Neonatal hemorrhage with increased PT and aPTT but normal bleeding time, because neonates don’t have the flora to produce Vit K yet so need an IM injection. Also can happen after antibiotics
Vitamin C 4 Functions
Antioxidant
Facilitates Fe absorption be reducing it to Fe2+
Hydroxylation of Pro and Lys for collagen synthesis
Necessary for Beta-hydroxylase which converts DA to NE
