1. Which of the following functions of vitamin B-12 is notrelated to the functions of folate?

A. Maintaining myelin sheaths

B. Transfer of methyl groups

C. Homocysteine metabolism

D. DNA synthesis

2. Plants _______.

A. are a rich source of vitamin B-12

B. are not sources of vitamin B-12

C. contain about the same amount of vitamin B-12 as is found inanimal foods, such as liver

D. can make vitamin B-12 in the presence of folate

3.With excessive intakes of vitamin C, increased urinaryexcretion of ______ (a by-product of vitamin C metabolism) maycause kidney stone formation in susceptible individuals.

A.oxalate

B. pyruvate

C. phosphate

D. uric acid

4.Which have vitamin-like compounds that have antioxidantfunctions in the body?(select those thatapply)

A.Taurine

B.Choline

C.Carnitine

D. Lipoic

E. Inositol

5. Why are older adults at increased risk for vitamin B-12deficiency compared to younger people?

A. As you age, your macula begins to turn yellow—a sign ofexcessive folate absorption, which masks vitamin B-12deficiency.

B. As you age, your metabolism slows and a rapid metabolism isrequired for optimal vitamin B-12 absorption.

C. As you age, your bones become more porous; porous bones donot absorb vitamin B-12 as well as dense bones do.

D. As you age, your stomach produces less acid, which limitscleavage of vitamin B-12 from food. In addition, decreasedproduction of intrinsic factor by the stomach limits vitamin B-12absorption.