Vitamins

Question 1

Vitamin A

Answer 1

Retinol/B-carotene

Visual pigments of retina; regulation of gene expression and cell differentiation (epithelium)

Night blindness; xerophthalmia; keratinization of skin

Question 2

Vitamin D

Answer 2

Calciferol

Maintenance of calcium balance; enhances intestinal absorption of Ca and mobilizes bone mineral; regulation of gene expression and cell differentiation

Rickets = poor mineralization of bone
Osteomalacia = bone demineralization

Question 3

Vitamin E

Answer 3

Tocopherols, tocotrienols

Antioxidant, especially cell membranes; roles in cell signaling

Serious neurologic dysfunction – extremely rare

Question 4

Vitamin K

Answer 4

Phylloquinone: menaquinones

Coenzyme in formation of y-carboxyglutamate in enzymes of blood clotting and bone matrix

Impaired blood clotting, hemorrhagic disease

Question 5

Vitamin B1

Answer 5

Thiamin

Coenzyme in pyruvate and a-ketoglutarate dehydrogenases, and transketolase; regulates Cl- channel in nerve conduction

Beriberi (Peripheral nerve damage) or central nervous system lesions (Wernicke-Korsakoff syndrome)

Question 6

Vitamin B2

Answer 6

Riboflavin

Coenzyme in oxidation and reduction reactions; prosthetic group of flavoproteins

Question 7

Niacin

Answer 7

Nictonic acid, nicotinamide

Coenzyme in oxidation and reduction reactions, functional part of NAD and NADP; role in intracellular calcium regulation and cell signaling

Pellegra - photosensitive dermatitis, depressive psychosis

Question 8

Vitamin B6

Answer 8

Pyridoxine, pyridoxal, pyridoxamine

Coenzyme in transamination and decarboxylation of amino acids and glycogen phosphorylase; modulation of steroid hormone action

Disorders of amino acid metabolism, convulsions

Question 9

Folic acid

Answer 9

Coenzyme in transfer of one-carbon fragments

Megaloblastic anemia

Question 10

Vitamin B12

Answer 10

Cobalamin

Coenzyme in transfer of one carbon fragments and metabolism of folic acid

Pernicious anemia = megaloblastic anemia with degeneration of the spinal cord

Question 11

Pantothenic acid

Answer 11

Functional part of CoA and acyl carrier protein; fatty acid synthesis and metabolism

Peripheral nerve damage (nutritional melalgia or “burning foot syndrome”

Question 12

Vitamin H

Answer 12

Biotin

Coenzyme in carboxylation reactions in gluconeogenesis and fatty acid synthesis; role in regulation of cell cycle

Impaired fat and carbohydrate metabolism

Question 13

Vitamin C

Answer 13

Ascorbic acid

Coenzyme in hydroxylation of proline and lysine in collagen synthesis; antioxidant; enhances absorption of iron

Scurvy – impaired wound healing, loss of dental cement, subcutaneous hemorrhage