VitaminAlt. NameFunctionDeficiencyExcessOther

ARetinolAntioxidant; constituent of visual pigments; essential for normal differentiation of epithelial cells into specialized tissue (pancreatic cells, mucus-secreting cells); prevents squamous metaplasia. Used to treat measles and AML subtype M3. Night blindness (nyctalopia); dry, scaly skin (xerosis cutis); corneal degeneration (keratomalacia); bitot spots on conjunctiva; immunosuppression (esp. measles).Acute Toxicity- n/v, vertigo, blurred visionChronic Toxicity- alopecia, dry skin (scaliness), hepatic toxicity and enlargement, arthralgias, and pseudotumor cerebri.Teratogenic (cleft palate, cardiac abnormalities), therefore a neg. pregnancy test and reliable contraception are required before isoretinoin (vit A derivative) is prescribed for severe acne. Retinol = vit A, so think retin-A (used topically for wrinkles and acne).

Sources: liver, leafy veggies

B1ThiamineIn TPP, which is a cofactor for dehydrogenase enzyme rxn: -Pyruvate deh. (links glycolysis to TCA cycle)-a-ketoglutarate deh. (TCA cycle)-Transketolase (HMP shunt)-branched chain ketoacid deh. Impaired glucose breakdown ATP depletion worsened by glucose infusion; highly aerobic tissues affected first.Wernicke: triad of confusion, opthalmoplegia, ataxiaWernicke-Korsakoff: triad + confabulation, personality change, memory loss (permanent); damage to medial dorsal nucleus of thalamus, mammillary bodiesDry Beri Beri: symmetrical peripheral neuropathy, sensory and motor impairments esp distal extremities; polyneuritis, symmetrical muscle wastingWet Beri Beri: high output cardiac failure (dilated cardiomyopathy), edemaInfantile beri beri: onset btwn 2-3 months; fulminant cardiac syndrome w/ cardiomegaly, tachycardia, cyanosis, dyspnea, vomiting

Dx: made by increase in RBC transketolase activity following vit B1 administration

B2RiboflavinComponent of flavins FAD and FMN, used as cofactors in redox rxns, e.g. succinate dehydrogenase rxn in TCA cycleCheilosis (inflammation of lips, scaling, fissures at corners of mouth), corneal vascularization; stomatitis, glossitis, dermatitis, ariboflavinosis

B3NiacinConstituent of NAD+, NADP+ (used in redox rxns); derived from Trp; Synthesis requires B2 and B6; Used to tx dyslipidemia; lowers VLDL and raises HDLGlossitis. Severe deficiency pellagra which can be caused by: 1) Hartnup ds (decreased Trp absorption); 2) malignant carcinoid syndrome (increased Trp metabolism); 3) Isoniazid (decreases vit B6)

Sx: Diarrhea, Dementia, Dermatitis (broad collar rash), hyperpigmentation of sun-exposed limbsSide Effects: flushing, warmth, itching

B5Panthothenic AcidEssential component of coenzyme A and fatty acid synthase.Dermatitis, enteritis, alopecia, adrenal insufficiency.

B6 PyridoxineConverted to pyridoxal phosphase (PLP), a cofactor used in transamination, decarboxylation rxns, glycogen phosphorylase. Synthesis of cystathionine, heme, niacin, histamine, and nerotransmitters, inc. serotonin, epinephrine, norepi, dopamine, and GABA. Convulsions, hyperirritability, peripheral neuropathy (deficiency inducible by isoniazid and oral contraceptives), sideroblastic anemias due to impaired Hgb synthesis and iron excess.

Cheilosis, glossitis, dermatitis

B7BiotinCofactor for carboxylation enzymes (which add a 1-C group):-pyruvate carboxylase: pyruvate (3C) oxaloacetate (4C)-acetyl-CoA carboxylase: acetyl-CoA (2C) malonyl-CoA (3C)-Propionyl CoA Carboxylase: Propionyl CoA (3C) methylmalonyl CoA (4C)Relatively rare. Dermatitis, alopecia, enteritis. Caused by Ab use or excessive ingestion of raw egg white. (Avidin in egg whites binds avidly to biotin)

B9FolateConverted to THF, a coenzyme for 1-C transfer/methylation reactions. Important for the synthesis of N bases in DNA and RNA. Macrocytic, megaloblastic anemia; hypersemented PMNs; glossitis; no neuro sx (vs. B12).Labs: increased homocysteine, normal methylmalonic acid levels. Most common vit deficiency in USA. Seen in alcoholism and pregnancy. Caused by drugs: phenytoin, sulfonamides, methotrexate. Supplement maternal folic acid early to prevent neural tube defects. Found in leafy green veggies. Absorbed in jejunum. Small reserve in liver.

B12CobalaminCofactor for homocystein methyltransferase (transfers CH3 groups as methylcobalamin) and methylmalonyl-CoA mutase. Classic Pernicious Anemia: older, mentally slow woman, N. European descent, lemon colored (anemic and icteric), smooth shiny tongue (atrophic glossitis), broad based shuffling gait

Macrocytic, megaloblastic anemia; hypersegmented PMNs; paresthesias and subacute combined degeneration (dorsal columns, lateral corticospinal tracts, and spinocerebellar tracts) due to abnormal myelin. Associated w/ increased serum homocysteine and methylmalonic acid levels. Prolonged deficiency irreversible nerve damage. Caused by insuffieicnt intake (vegan), malabsorption (sprue, enterieis etc.), lack of intrinsic factor (pernicious anemia, gastric bypass), or absence of terminal ileum (Crohns).Dx: anti-intrinsic factor AbsFound in animal products. Synthesized only by microorganisms. Very large, prolonged reserve in liver.

CAscorbic AcidAntioxidant; facilitates Fe absorption by reducing it to Fe2+ state. Necessary for hydroxylation of Pro and Lys in collagen synthesis. Necessary for dopamine beta-hydroxylase, which converts dopamine to NE. Scurvy swollen gums, bruising, petechiae, hemarthrosis, anemia, poor wound healing, perifollicular and subperiosteal hemorrhages, corkscrew hairWeakened immune response to local infxn. N/V, diarrhea, fatigue, Ca oxalate nephrolithiasis. Can increase risk of Fe toxicity in predisposed individuals (e.g. those with transfusions, hereditary hemochromatosis). Found in fruits and vegetables. Ancillary tx for methemoglobinemia by reducing Fe3+ to Fe2+.

DIncrease intestinal absorption of Ca and Phosphate; increase bone mineralizationRickets in kids (bone pain and deformity), osteomalacia in adults (bone pain and muscle weakness), hypocalcemic tetany.Breastfed infants should receive oral vit D. Deficiency exacerbated by low sun exposure, pigemneted skin, prematurity. HYpercalcemia, hypercalciuria, loss of appetite, tupor. Seen in granulomatous disease (increased activation of vti D by epithelioid macs)D2=ergocalciferol (plants)D3=cholecalciferol (milk, sun exposed skin stratum basale)25-OH D3= storage form1,25-(OH)2 D3= calcitriol, active form

ETocopherol, TocotrienolAntioxidant protects RBCs and membranes from free radical damageHemolytic anemia, acanthocytosis, muscle weakness, post. column and spinocerebellar tract demyelination.

Neuro presentation may seem similar to B12 def but w/o megaloblastic anemia, hypersegmented neutrophils, or increased serum methylmalonic acid levels. Can enhance anticoagulant effects.

KPhytomenadione, Phylloquinone, PhytonadioneCofactor for gamma-carboxylation of glutamic acid residues on various proteins required for clotting. Synthesized by intestinal flora. Necessary for maturation of clotting factors 2, 7, 9, 10, C, and S. Neonatal hemorrhage w/ increase PT and aPTT but normal bleeding time. Neonates cannot synthesize vit K b/c sterile intestines. Can also occur after prolonged use of broad spectrum Abx.Warfarin is a vit K antagonist. Not in breast milk.. Give neonates vit K injection at birth to prevent hemorrhagic disease of newborn.

ZincEssential for activity of 100+ enzymes. Important in formation of zinc fingers (transcription factor motif).Delayed wound healing, hypogonadism, decreased adult hair (axillary, facial, pubic), dysgeusia, anosmia, acrodermatitis enteropathica. May predispose to alcoholic cirrhosis.