FA Bioichem 3 vit

B1

B2

B3

B5

B6

B7

B9

B12

C

measles and AML, subtype M3.

Night blindness (nyctalopia); dry, scaly skin(xerosis cutis); alopecia; corneal degeneration(keratomalacia); immune suppression.

Arthralgias, skin changes (e.g., scaliness), alopecia, cerebral edema, pseudotumor cerebri, osteoporosis, hepatic abnormalities.Teratogenic (cleft palate, cardiac abnormalities), so a (-) pregnancy test and reliable contraception are needed before isotretinoin is prescribed for severe acne

In thiamine pyrophosphate (TPP), a cofactor for several dehydrogenase enzyme

• Think ATP: α-ketoglutarate dehydrogenase,Transketolase, and Pyruvate dehydrogenaseƒƒ
• -Transketolase (HMP shunt)ƒƒ
• -Pyruvate dehydrogenase (links glycolysis to TCA cycle)
• -ƒ α-ketoglutarate dehydrogenase (TCA cycle)ƒƒ

-Branched-chain ketoacid dehydrogenase

Impaired glucose breakdown Ž ATP depletion worsened by glucose infusion; highly aerobic tissues (e.g., brain, heart) are affected first.Wernicke-Korsakoff syndrome and beriberi.Seen in malnutrition and alcoholism (2° tomalnutrition and malabsorption).

Diagnosis made by inc in RBC transketolase activity following vitamin B1 administration.

confusion,ophthalmoplegia, ataxia (classic triad) + confabulation, personality change, memory loss (permanent). Damage to medial dorsal nucleus of thalamus, mammillary bodies

polyneuritis, symmetrical muscle wasting.

high-output cardiac failure(dilated cardiomyopathy), edema

• FAD and FMN are derived from riboFlavin(B2 = 2 ATP).
• Component of flavins FAD and FMN, used as cofactors in redox reactions, e.g., the succinate dehydrogenase reaction in the TCA cycle.

• The 2 C’s of B2.
• Cheilosis (inflammation of lips, scaling and fissures at the corners of the mouth), Corneal vascularization.

• NAD derived from Niacin (B3 = 3 ATP). 
• Constituent of NAD+, NADP+ (used in redox reactions). Derived from tryptophan. Synthesis requires vitamins B2 and B6. Used to treat dyslipidemia; lowers levels of VLDL and raises levels of HDL.

Glossitis. Severe deficiency leads to pellagra,which can be caused by Hartnup disease( tryptophan absorption), malignant carcinoid syndrome ( tryptophan metabolism),and isoniazid ( vitamin B6).

Diarrhea, Dementia (alsohallucinations), Dermatitis (e.g., Casal necklace or hyperpigmentation of sun-exposedlimbs).

Facial flushing (induced by prostaglandin, not histamine), hyperglycemia, hyperuricemia.

• B5 is “pento”thenate
• Essential component of coenzyme A (CoA,a cofactor for acyl transfers) and fatty acid synthase.

Dermatitis, enteritis, alopecia, adrenal insufficiency.

Converted to pyridoxal phosphate, a cofactor used in transamination (e.g., ALT and AST),decarboxylation reactions, glycogen phosphorylase. Synthesis of cystathionine, heme, niacin,histamine, and neurotransmitters including serotonin, epinephrine, norepinephrine, dopamine,and GABA.

Convulsions, hyperirritability, peripheral neuropathy (deficiency inducible by isoniazid and oral contraceptives), sideroblastic anemias due to impaired hemoglobin synthesis and iron excess.

• Cofactor for carboxylation enzymes (which adda 1-carbon group):
• -Pyruvate carboxylase: pyruvate (3C)Ž -->oxaloacetate (4C)ƒƒ
• -Acetyl-CoA carboxylase: acetyl-CoA (2C)Ž --> malonyl-CoA (3C)ƒƒ
• -Propionyl-CoA carboxylase: propionyl-CoA(3C) -->Ž methylmalonyl-CoA (4C)

“Avidin in egg whites avidly binds biotin.”

Relatively rare. Dermatitis, alopecia, enteritis.Caused by antibiotic use or excessive ingestion of raw egg whites.

Converted to tetrahydrofolate (THF), a coenzyme for 1-carbon transfer/methylation reactions.Important for the synthesis of nitrogenous bases in DNA and RNA.

Absorbed in jejunum.

Macrocytic, megaloblastic anemia;hypersegmented polymorphonuclear cells(PMNs); glossitis; no neurologic symptoms(as opposed to vitamin B12 deficiency). Labs: high homocysteine, normal methylmalonica cid. Most common vitamin deficiency inthe United States. Seen in alcoholism and pregnancy.

Deficiency can be caused by several drugs (e.g.,phenytoin, sulfonamides, methotrexate).Supplemental maternal folic acid in early pregnancy decreases risk of neural tube defects.

Cofactor for homocysteine methyltransferase(transfers CH3 groups as methylcobalamin)and methylmalonyl-CoA mutase.

Macrocytic, megaloblastic anemia;hypersegmented PMNs; paresthesias,and subacute combined degeneration(degeneration of dorsal columns, lateral corticospinal tracts, and spinocerebellar tracts)due to abnormal myelin. Associated with serum homocysteine and methylmalonicacid levels. Prolonged deficiency Ž irreversiblenerve damage.

B12

Antioxidant.Also facilitates iron absorption by reducing it to Fe2+ state.Necessary for hydroxylation of proline andlysine in collagen synthesis.Necessary for dopamine β-hydroxylase, which converts dopamine to NE.

Scurvy—swollen gums, bruising, hemarthrosis,anemia, poor wound healing, perifollicular and subperiosteal hemorrhages, “corkscrew”hair.Weakened immune response.

Nausea, vomiting, diarrhea, fatigue, calcium oxalate nephrolithiasis. Can  risk of iron toxicity in predisposed individuals(e.g., those with transfusions, hereditaryhemochromatosis).

with vit C ; Ancillary treatment for methemoglobinemia by reducing Fe3+ to Fe2+.

inc intestinal absorption of calcium andphosphate,  bone mineralization.

ergocalciferol—ingested from plants

cholecalciferol—consumed in milk,formed in sun-exposed skin (stratum basale). 25-OH D3 = storage form. 1,25-(OH)2 D3 (calcitriol) = active form.

Rickets  in children (bone pain and deformity), osteomalacia in adults (bone pain and muscle weakness), hypocalcemic tetany.Breastfed infants should receive oral vitaminD. Deficiency is exacerbated by low sun exposure, pigmented skin, prematurity.

Hypercalcemia, hypercalciuria, loss of appetite,stupor. Seen in sarcoidosis ( activation ofvitamin D by epithelioid macrophages).

Antioxidant (protects erythrocytes and membranes from free radical damage).

• Hemolytic anemia, acanthocytosis,muscle weakness, posterior column and spinocerebellar tract demyelination.
• Neurological presentation may appear similarto vitamin B12 deficiency, but withoutmegaloblastic anemia, hypersegmentedneutrophils, or high serum methylmalonic acidlevels.

Cofactor for the γ-carboxylation of glutamic acid residues on various proteins required for blood clotting. Synthesized by intestinal flora.

Neonatal hemorrhage with high PT and high aPTT but normal bleeding time (neonates havesterile intestines and are unable to synthesizevitamin K). Can also occur after prolonged use of broad-spectrum antibiotics.

Essential for the activity of 100+ enzymes. Important in the formation of zinc fingers (transcriptionfactor motif).

Delayed wound healing, hypogonadism, low adult hair (axillary, facial, pubic), dysgeusia, anosmia,acrodermatitis enteropathica. May predispose to alcoholic cirrhosis.

autosomal recessive metabolic disorder affecting the uptake of zinc, characterized by periorificial (around the natural orifices) and acral (in the limbs)dermatitis, alopecia (loss of hair), and diarrhea.