31. Why does vitamin B12 absorption decrease with age?

A. a reduction in hydrochloric acid in the stomach

B. a reduction in intrinsic factor production

C. a lack of necessary pancreatic enzymes

D. all of the above

32. Which vitamin acts as an antioxidant and helps neutralize free radicals?

A. vitamin C

B. biotin

C. pantothenic acid

D. pyridoxine

33. Which vitamin is needed during transamination to create nonessential amino acids?

A. biotin

B. vitamin B6

C. vitamin C

D. vitamin B12

34. A sign of a B6 deficiency is

A. pellagra.

B. beriberi.

C. microcytic hypochromic anemia.

D. pernicious anemia.

35. Which of the following is correct about riboflavin?

A. Its active form is coenzyme A.

B. It is only found in animal foods.

C. It is important in the synthesis of collagen.

D. Ariboflavinosis is the name for its deficiency.

36. Which of the following is a function of biotin?

A. It helps prevent scurvy.

B. It helps to reduce cholesterol.

C. It has an antioxidant effect on free radicals.

D. It acts as a coenzyme in fatty-acid synthesis.

37. A food source rich in biotin is

A. spinach.

B. peanuts.

C. egg whites.

D. white flour.

38. Which vitamin is found in so many foods that its name is derived from a word meaning “everywhere”?

A. thiamin

B. niacine

C. riboflavin

D. pantothenic acid

39. Milk, yogurt, and grains are rich sources of which vitamin?

A. thiamin

B. riboflavin

C. vitamin C

D. vitamin B12

40. Which of the following is not a symptom of riboflavin deficiency?

A. reduced conversion of vitamin B6 to its active form

B. inflamed tissues in the mouth and throat

C. soreness in the soles of the feet

D. altered iron metabolism