41.Which of the following is the major form of niacin in the blood?

a.nicotene

b.nicotinic acid

c.niacin phosphate

d.nicotinamide

42.Which of the following properties is shared by niacin and riboflavin coenzymes?

a.unstable to irradiation

b.unstable to metal cooking utensils

c.acceptance and transfer of hydrogen atoms

d.acceptance and transfer of carboxyl groups

43.Which of the following amino acids can the body use to synthesize niacin when the diet contains an adequate amount of protein?

a.lysine

b.valine

c.tryptophan

d.phenylalanine

44.Which of the following nutrients functions to prevent the appearance of a bilateral, symmetrical dermatitis, primarily on areas exposed to the sun?

a.niacin

b.choline

c.inositol

d.riboflavin

45.The vitamin deficiency disease pellagra means which of the following?

a.“rough skin”

b.“paralyzed limbs”

c.“demented behaviour”

d.“flattened erythrocytes”

46.A low-protein diet in which corn is a principal food has been found to cause a deficiency of which of the following vitamins?

a.niacin

b.thiamin

c.vitamin C

d.vitamin B₁₂

47.What vitamin deficiency disease appeared in people who had subsisted on a diet high in corn and low in protein?

a.scurvy

b.pellagra

c.wet beriberi

d.pernicious anemia

48.Which of the following is among the common signs of pellagra?

a.dehydration

b.dementia

c.dysphagia

d.desiccation

49.A general niacin deficiency is known to be manifested in abnormalities of which one of the following organs/systems?

a.endocrine system

b.skeletal system

c.nervous system

d.cardiovascular system

50.Tryptophan can be used in the body to synthesize which of the following nutrients?

a.FAD

b.biotin

c.niacin

d.inositol