Vitamin D

The UL for vitamin D is: 1) 4,000 IU (100 micrograms) 2) 8,000 IU ( 200 micrograms) 3) There is no UL for vitamin D.

1) 4,000 IU (100 micrograms)

Biopsies of muscle in those with vitamin D deficiency show: 1) atrophy of primarily type II (fast-twitch) muscle fibers. 2) apoptisis of the myocytes in type I (fast-twitch) muscle fibers. 3) apoptisis caused by phagocytosis of the type II (fast-twitch) muscle fibers. 4) hypertrophy of a significant amount of type I (fast-twitch) muscle fibers.

1) atrophy of primarily type II (fast-twitch) muscle fibers.

________ is the form of vitamin D that is the major circulating form with a half-life of approximately _____weeks. 1) Calcidiol; three 2) Calcitriol; four 3) Cholecalciferol; two 4) Vitamin D2; five

1) Calcidiol; three

Which of the following conditions is known to lead to formation of mineral deposits in the blood vessels and kidney? 1) Excessive intake of vitamin D 2) Inadequate intake of vitamin D 3) Excessive intake of tocopherols 4) Inadequate intake of tocopherols

1) Excessive intake of vitamin D

Which of the following is NOT a major target organ for the action of activated vitamin D? 1) Liver 2) Bone 3) Kidney 4) Intestine

1) Liver

Which of the following is/are true? 1) Vitamin D is a steroid. 2) Vitamin D is a water-soluble vitamin. 3) The "provitamin" form of vitamin D is found in high fat plant foods like avocadoes and mushrooms. 4) All are true. 5) All are false.

1) Vitamin D is a steroid.

What is a symptom of a vitamin D toxicity? 1) hypercalcemia 2) hypocalcemia 3) rickets 4) osteoporosis

1) hypercalcemia

The mechanism/s that ensure/s that cutaneous synthesis does not cause vitamin D toxicity is: 1) previtamin D-3 has a very weak affinity for the vitamin-D binding protein. 2) calcitriol exerts feedback inhibition on 7-dehydrocholesterol synthesis. 3) calcitriol acts as an allosteric inhibitor for the enzymes that stimulate hydroxylation of cholesterol. 4) A combination of all of the above.

1) previtamin D-3 has a very weak affinity for the vitamin-D binding protein.

In what system would the effects of a vitamin D deficiency be most readily observed? 1) Nervous 2) Skeletal 3) Muscular 4) Circulatory

2) Skeletal

In the liver the enzyme ___________________________functions to hydroxylate vitamin D at carbon 25 to form 25-OH cholecalciferol. 1) vitamin D carboxylase 2) cholecalciferol dehydrogenase 3) 25-hydroxylase 4) cholecalciferal 1-25-dihydroxylase

3) 25-hydroxylase

Where is calbindin primarily found in the body? 1) Liver 2) Kidneys 3) Intestine

3) Intestine

All of the following are other names for vitamin D EXCEPT 1) calcitriol. 2) calciferol. 3) calcitonin. 4) cholecalciferol.

3) calcitonin.

The vitamin D response element (VDRE) is found 1) on the enterocyte membrane. 2) on the renal tubule. 3) in the nucleus. 4) in the pancreatic duct cell. 5) on the stellate cells of the liver

3) in the nucleus.

If asked about the relationship of vitamin D to autoimmune disease, the best information for a health professional to tell is: 1) the evidence does not support a relationship at this time. 2) the evidence is only in animals, not humans. 3) some evidence suggests a protective effect of vitamin D. 4) take a supplement containing 2000 IU vitamin D each day.

3) some evidence suggests a protective effect of vitamin D.

Which of the following can the body use to synthesize vitamin D? 1) Bone 2) Carotene 3) Tryptophan 4) Exposure to sunlight

4) Exposure to sunlight

Which water soluble vitamin-derived coenzyme is involved in vitamin D activation? 1) FAD 2) TPP 3) Coenzyme A 4) NADP

4) NADP

If a 60 year old female wanted to consume her RDA for vitamin D by drinking milk, how much fluid milk should she consume each day? 1) Two 2) Three 3) Four 4) Six

4) Six

Which of the following organs is NOT required for the complete synthesis of activated vitamin D? 1) Skin 2) Liver 3) Kidney 4) Small intestine

4) Small intestine

Which vitamin D molecule would you expect to see in fortified foods? 1) ergocalciferol - vitamin D2 2) calcidiol - 25-OH D3 3) calcitriol - 1,25-OH2 D3 4) cholecalciferol - vitamin D3

4) cholecalciferol - vitamin D3

All of the following are characteristics of vitamin D nutrition EXCEPT 1) deficient intake may lead to altered bone composition. 2) excessive intake may lead to mineral deposits in the kidneys. 3) fortified milk is the major dietary source in the U.S. population. 4) the requirement is increased in most people who are exposed to the sun

4) the requirement is increased in most people who are exposed to the sun.