11. Synthesis of the active hormonal form of vitamin D is the result of the combined action of the

a. skin, liver, and kidney.

b. pancreas, thyroid, and liver.

c. skin, skeleton, and liver.

d. kidney, skeleton, and liver.

12. The last organ involved in the production of the physiologically active form of vitamin D is the

a. liver.

b. kidney.

c. intestine.

d. skin.

13. The primary function of vitamin D is to regulate the absorption and metabolism of the minerals

a. sodium and potassium.

b. iron and phosphorus.

c. calcium and phosphorus.

d. sodium and calcium.

14. A vitamin D deficiency in growing children that results in the malformation of skeletal tissue, especially the long bones, is referred to as

a. rickets.

b. scurvy.

c. pellagra.

d. beriberi.

15. Recommended intakes for vitamin D are difficult to establish because

a. exposure to sunlight varies.

b. it is present in so many foods.

c. the body stores such large amounts.

d. the amount in food varies with the season.

16. A toxic level of vitamin D is most likely to result in

a. liver damage.

b. hyperpigmentation.

c. blindness.

d. calcification of soft tissues.

17. Sunflower oil is a rich source of

a. vitamin A.

b. vitamin B.

c. vitamin D.

d. vitamin E.

18. The requirement for vitamin E varies by the amount of an individual’s

a. sun exposure.

b. dietary selenium.

c. animal fat intake.

d. polyunsaturated fatty acid intake.

19. Vitamin E protects membranes because it acts as a(n)

a. barrier.

b. peroxide.

c. antioxidant.

d. clotting factor.

20. The fat-soluble vitamin responsible for the synthesis of blood-clotting factors by the liver is vitamin

a. A.

b. D.

c. E.

d. K.