Vitamins

Question 1

Vit A

Answer 1

Retinol

• antioxidant, visual pigments, needed for differentiation of epithelial cells into specialized tissue, prevents squamous metaplasia
• Def = night blindness, dry/scaly skin, corneal degeneration, bitot spots, immunosuppression
• Used for cystic acne and APL

Question 2

Vit B1

Answer 2

Thiamine

• TPP is cofactor for… ATP (alpha keto-glut dehydrogenase, transketolase, pyruvate dehydrogenase) and branched chain ketoacid dehydrogenase
• Def = impaired glucose breakdown –> dec ATP (brain and heart); unresponsive to dextrose so replace B1 b/f

Ber1Ber1 (dry - polyneuritis and muscle wasting v. wet - high output cardiac fail and edema)

Wernicke-Korsakoff - confusion + opthalmoplegia + ataxia

Question 3

Vit B2

Answer 3

Riboflavin

• FAD (2 ATP for vit B2) and FMN
• Needed for succinate dehydrogenase in TCA
• Def = 2 C’s (cheliosis, corneal vascularization)

Question 4

Vit B3

Answer 4

Niacin

• NAD+ and NADP+ (3 ATP)
• Made from trypotophan w/ B2 and B6
• Def = 3 D’s (dementia, diarrhea, dermatitis in broad collar area); pellagra

Question 5

Vit B5

Answer 5

Pantothenic Acid

• CoA and FA synthase
• Def = dermatitis, enteritis, alopecia, adrenal insufficiency

Question 6

Vit B6

Answer 6

Pyridoxine

-PLP is cofactor for … ALT/AST, decarboxylations, glycogen phosphorylase, synthesis of heme, niacin, histamine, serotonin, epi, NE, dopamine, GABA

Dec = convulsions, peripheral neuropathy, hyper-irritable, sideroblastic anemia

Question 7

Vit B7

Answer 7

Biotin

-Carboxylations (add carbon group)

• Pyruvate –> OAA
• Acetyl CoA –> malonyl CoA
• propionyl CoA –> methylmalonyl CoA

Def = RARE but dermatitis, alopecia, enteritis (associated w/ raw eggs b/c white bind biotin)

Question 8

Vit B9

Answer 8

Folate

• Converted –> THF for 1 methyl transfer and methylation
• DNA/ RNA synthesis
• Def = macrocytic anemia and hyper-segmented PMNs w/ normal methylmalonic acid and no neuro symptoms

Question 9

Vit B12

Answer 9

Cobalamin

• Methionine synthase & methylmalonyl CoA mutase
• Def = macrocytic anemia and hyper-segmented PMNs w/ inc methlymalonic acid and homocysteine w/ abnormal myelin so dorsal columns and later tracts

Question 10

Vit C

Answer 10

Ascorbic Acid

• Antioxidant, inc iron absorption by reducing it to Fe+2 state
• Also needed for hydroxylation in collagen synthesis (scurvy)
• Def = swollen gums, bruising, petechiae, hemarthosis, anemia, poor wound healing, corkscrew hair, weak immune system

Question 11

Vit D

Answer 11

D2 - ergocalciferol (plants)
D3 - cholecalciferol (milk, skin)

• Inc absorption of Ca and phos in intestine
• Def = Rickets (bow legs), osteomalacia (bone pain and weakness in adults), hypocalcemic tetany
• Excess = inc Ca, loss of appetite, stupor

Question 12

Vit E

Answer 12

Tocopherol/tocotrienol

• Antioxidant (protects RBCs and membranes from free radical damage)
• Def = neuro similar to B12 w/o megaloblastic anemia, inc methylmalonic acid or hyper-segmented PMNs

Question 13

Vit K

Answer 13

Activated by epoxide reductase –> cofactor fo carboxylation of glutamic acid residues on clotting factors (2, 7, 9, 10, protein C and protein S)

Synthesized by intestinal flora (can be deficient in neonates and after long-term abx b/c dec intestinal flora)

Question 14

Zinc

Answer 14

Def = delayed wound healing, hypogonadism, dec adult hair, ansomnia, acrodermatitis enteropathica

May also predispose to alcoholic cirrhosis