I. Start the exam by click the “Start” button
Vitamin D
See all quizzes of Vitamin D at here:
1 Vitamin D is better related to which of the following ?
A. Vitamin
B. Hormone
C. Enzyme
D. All of the above
2 UV radiation of skin leads to synthesis of Vitamin D from ?
A. 5-dehydrocholesterol
B. 6-dehydrocholesterol
C. 7-dehydrocholesterol
D. 8-dehydrocholesterol
3 Which of the following statements about Vitamin D is false ?
A. Vitamin D from plant sources is vitamin D2
B. Vitamin D from animal sources is vitamin D3
C. D2 has more biologic activity than D3
D. 25(OH)D is major circulating &storage form of vitamin D
4 The half-life of 25(OH)D is approximately ?
A. 1 – 12 hours
B. 1 – 2 weeks
C. 2 – 3 weeks
D. 4 – 6 weeks
5 The formation of the mature Vitamin D hormone occurs in ?
A. Liver
B. Kidney
C. Skin
D. All of the above
6 Drugs associated with increased risk of generalized osteoporosis
in adults include all except ?
A. Aluminum
B. Gonadotropin-releasing hormone agonists
C. Protamine
D. Lithium
7 Biochemical markers of bone formation include all except ?
A. Serum bone-specific alkaline phosphatase
B. Serum bone sialoprotein
C. Serum osteocalcin
D. Serum propeptide of type I procollagen
8 Biochemical markers of bone resorption include all except ?
A. Serum tartrate-resistant acid phosphatase
B. Serum bone sialoprotein
C. Serum osteocalcin
D. Urine hydroxyproline
9 25(OH)D-1 hydroxylase is expressed in ?
A. Proximal convoluted tubule cells
B. Cells of loop of Henle
C. Distal convoluted tubule cells
D. All of the above
10 1 hydroxylase is produced in the granulomas of ?
A. Sarcoidosis
B. Tuberculosis
C. Berylliosis
D. All of the above
11 Vitamin D receptor (VDR) is what kind of a receptor ?
A. Cell membrane
B. Nuclear
C. Mitochondrial
D. Endoplasmic reticulum
12 Normally, Vitamin D receptor (VDR) has maximum affinity for ?
A. 25(OH)D2
B. 25(OH)D3
C. 1,25(OH)2 D
D. All of the above
13 Active transport of calcium across enterocytes is a function of ?
A. Calbindin 9K
B. ECaC
C. ICaC
D. All of the above
14 1,25(OH)2 D has an antiproliferative effect on ?
A. Keratinocytes
B. Breast cancer cells
C. Prostate cancer cells
D. All of the above
15 Accelerated loss of vitamin D due to increased metabolism is due
to all except ?
A. Barbiturates
B. Phenytoin
C. Rifampin
D. Isoniazid
16 Impaired 1 hydroxylation leading to improper activation of
vitamin D is due to all except ?
A. Hypoparathyroidism
B. Renal failure
C. Liver disease
D. Ketoconazole
17 Which of the following drugs causes impaired 25-hydroxylation
of Vitamin D3 ?
A. Phenytoin
B. Rifampin
C. Isoniazid
D. Ketoconazole
18 Radiologic feature of osteomalacia ‘Looser’s zones’ is related to ?
A. Nerves
B. Arteries
C. Veins
D. Lymph nodes
19 In patients whose 1 hydroxylation is impaired, which of the
following vitamin D analogues is given ?
A. Dihydrotachysterol (DHT)
B. 1,25(OH)2 D3
C. 1 hydroxyvitamin D2
D. Any of the above
20 What level of urinary calcium excretion predisposes to
nephrolithiasis ?
A. > 50 mg/day
B. > 100 mg/day
C. > 175 mg/day
D. > 250 mg/day
21 Burnett’s syndrome is related to ?
A. Aluminum Intoxication
B. Milk-Alkali Syndrome
C. Vitamin A Intoxication
D. Thiazides diuretics
