Vitamins Flashcards
Water-soluble vitamin names
B1 (thiamine; TPP) B2 (Riboflavin; FAD, FMN) B3 (Niacin; NAD+) B5 (Pantothenic acid; CoA) B6 (Pyridoxine; PLP) B7 (Biotin) B9 (Folate) B12 (Cobalamin) C (Ascorbic acid)
Vitamin A (retinol) [fxn, food]
> Antioxidant; found in visual retinal pigments.
Needed for differentiation of epithelial cells in specialized tissues (pancreatic, mucus cells).
Prevents squamous metaplasia.
Found in liver and leafy veggies.
Vitamin A
[toxicity]
> Acute: N/V, blurred vision, vertigo
Chronic: alopecia, dried skin, hepatic toxicity and enlargement; pseudotumor cerebri (papilledema w/ benign intracranial HTN)
Teratogenic (cleft palate, cardiac abnormalities, microcephaly)
Vitamin A
[deficiency]
Night blindness (nyctalopia) Dry, scaly skin (xerosis cutis) Corneal degeneration (keratomalacia)
Vitamin B1
[Fxn]
TPP cofactor in pyruvate DHG, alpha-ketoglutarate DHG, branched-chain ketoacid DHG, transketolase
Vitamin B1
[Deficiency]
> Wernicke-Korsakoff syndrome
Dry beriberi: polyneuritis, symmetrical muscle wasting
Wet beriberi: high-output cardiac failure (dilated cardiomyopathy), edema
*Seen in malnutrition, alcoholism
Vitamin B2
[fxn, deficiency]
> FAD, FMN – cofactors in redox rxns (ex. succinate DHG reaction in TCA cycle).
Def: Cheilosis, corneal vascularization.
Vitamin B3
[Fxn]
> NAD+, NADP+ – for redox reactions.
Derived from tryptophan – synthesis needs B2 and B6.
Treat dyslipidemia – lower VLDL, raise HDL
Vitamin B3
[deficiency]
> Glossitis.
Severe deficiency can cause Pellagra (ex. Hartnup dse, malignant carcinoid syndrome, isoniazid).
*Pellagra: Diarrhea, Dementia, Dermatitis
Vitamin B5
[Fxn, deficiency]
> for CoA, fatty acid synthase.
>Def: dermatitis, enteritis, alopecia, adrenal insufficiency
Vitamin B6
[Fxn, deficiency]
> converted to PLP cofactor – transamination (ALT, AST), decarboxylation, glycogen phosphorylation.
synthesis of cystathione, heme, niacin, histamine, neurotransmitters.
Def: convulsions, peripheral neuropathy, sideroblastic anemias (impaired Hgb synth and iron excess).
Vitamin B7
[fxn, deficiency]
> Cofactor for pyruvate carboxylase, acetyl-CoA carboxylase, propionyl-CoA carboxylase.
Def: rare; dermatitis, alopecia; antibiotic use or excessive ingestion of raw egg whites (biotin-binding Avidin).
Vitamin B9
[fxn, deficiency]
> Converted to THF – for 1-carbon transfer/methylation, synthesis of nitrogenous bases.
Found in leafy green veggies; absorbed in jejenum; storage in liver
Def: MC vit deficiency in US; Megaloblastic anemia w/ no neuro ssx.
Vitamin B12
[fxn, deficiency]
> cofactor for homocystine methyltransferase, methylmalonyl-CoA mutase.
found in animal products; synthesized only by microbes
need intrinsic factor for absorption in terminal ileum; storage in liver
Def: megaloblastic anemia w/ neuro ssx; subacute combined degeneration; pernicious anemia (anti-IF antibodies)
Vitamin C
[fxn]
> Antioxidant; found in fruits and veggies
needed for iron absorption – reduces iron to Fe2+ state (tx for methemoglobinemia)
hydroxylation of proline and lysine in collagen synthesis.
conversion of dopamine to NE (dopamine B-hydroxylase)
Vitamin C
[deficiency, toxicity]
> Def: Scurvy – swollen gums, bleeding, anemia, poor wound healing, corkscrew hair, perifollicular and subperiosteal hemorrhages.
Tox: iron toxicity in predisposed (transfusions), calcium oxalate nephrolithiasis
Vitamin D
[fxn]
D2: ergocalciferol (plants)
D3: cholecalciferol (milk, sun-exposed skin)
25-OH D3 (storage)
1,25-(OH)2 D3: calcitriol (active form)
>For intestinal absorption of Ca and phosphate; inc. bone mineralization.
*Breastfed infants should be given oral Vit D
Vitamin D
[Deficiency, toxicity]
> Def: Rickets in kids, Osteomalacia in adults
>Tox: seen in granulomatous diseases (inc. activation of Vit D by epithelioid macrophages)
Vitamin E (tocopherol/tocotrienol) [fxn, deficiency]
> Antioxidant (protects RBCs and membranes from free radical damage)
Def: hemolytic anemia, muscle weakness; demyelination of dorsal column, spinocerebellar tract
*Neuro ssx appear w/o megaloblastic anemia, hypersegmented neutrophils, or inc. methylmalonate (vs B12 deficiency)
Vitamin K (phytomenadione, phylloquinone, phytonadione) [fxn]
Cofactor for gamma-carboxylation of glutamate on clotting protein factors.
Synthesized by intestinal flora.
*Warfarin - vit K antagonist
Vitamin K
[Deficiency]
Neonatal hemorrhage (inc. PT, aPTT; normal BT)
>Neonates can’t yet synthesize vit K.
>not in breast milk – give vit K injection at birth to prevent hemorrhagic dse of newborn.
Zinc
[fxn, deficiency]
> needed for several enzymes; zinc fingers (transcription factor motif)
Def: delayed wound healing, hypogonadism; dec. adult hair; anosmia; acrodermatitis enteropathica
Kwashiorkor
PROTEIN malnutrition.
>Skin lesions, edema due to dec. plasma oncotic pressure.
>Liver malfunction (fatty change due to dec. apolipoproteins)
*Small child w/ swollen abdomen.
Marasmus
Total CALORIE malnutrition.
>tissue and muscle wasting, loss of subcutaneous fat, edema.
