CSS - PMS - CCE - PCS - General Science
Vitamins
Pancreatic insufficiency can predispose to deficiency of fat-soluble vitamins because of impaired:
A. Fat digestion
B. Intrinsic factor secretion
C. Folate transport only
D. Vitamin C synthesis
Correct Answer: A
A is correct because pancreatic enzyme deficiency causes fat maldigestion and therefore poor absorption of vitamins A, D, E and K.
CSS - PMS - CCE - PCS - General Science
Vitamins
Which condition can predispose to deficiency of vitamins A, D, E and K?
A. Cholestatic liver disease
B. Simple myopia
C. Essential hypertension alone
D. Seasonal allergic rhinitis
Correct Answer: A
A is correct because reduced bile delivery impairs micelle formation and absorption of fat-soluble vitamins.
CSS - PMS - CCE - PCS - General Science
Vitamins
Vitamin D deficiency can lead to secondary elevation of:
A. Parathyroid hormone
B. Insulin only
C. Thyroxine only
D. Cortisol only
Correct Answer: A
A is correct because low calcium absorption from vitamin D deficiency may trigger secondary hyperparathyroidism.
CSS - PMS - CCE - PCS - General Science
Vitamins
Which hormone stimulates renal 1-alpha-hydroxylase and therefore increases calcitriol production?
A. Parathyroid hormone
B. Insulin
C. Melatonin
D. Prolactin
Correct Answer: A
A is correct because parathyroid hormone stimulates renal activation of vitamin D when calcium is low.
CSS - PMS - CCE - PCS - General Science
Vitamins
In chronic kidney disease, reduced 1-alpha-hydroxylase activity can lower production of:
A. Calcitriol
B. Retinol
C. Ascorbic acid
D. Thiamine
Correct Answer: A
A is correct because kidney 1-alpha-hydroxylase produces calcitriol, so advanced kidney disease can reduce active vitamin D formation.
CSS - PMS - CCE - PCS - General Science
Vitamins
Which wavelength range of sunlight is most relevant to cutaneous vitamin D production?
A. UVB
B. UVC only
C. Infrared
D. Microwaves
Correct Answer: A
A is correct because UVB radiation drives conversion of 7-dehydrocholesterol to previtamin D3 in skin.
CSS - PMS - CCE - PCS - General Science
Vitamins
Which vitamin is synthesized from 7-dehydrocholesterol in human skin?
A. Vitamin D3
B. Vitamin A
C. Vitamin E
D. Vitamin K1
Correct Answer: A
A is correct because UVB converts 7-dehydrocholesterol in skin to previtamin D3, which becomes cholecalciferol.
CSS - PMS - CCE - PCS - General Science
Vitamins
Surgical removal of the terminal ileum most directly threatens absorption of:
A. Vitamin B12
B. Vitamin C
C. Vitamin B1
D. Vitamin B2
Correct Answer: A
A is correct because the intrinsic factor-B12 complex is absorbed in the terminal ileum.
CSS - PMS - CCE - PCS - General Science
Vitamins
Long-term metformin therapy may contribute to deficiency of:
A. Vitamin B12
B. Vitamin A
C. Vitamin E
D. Vitamin K
Correct Answer: A
A is correct because prolonged metformin use is associated with reduced vitamin B12 absorption in some patients.
CSS - PMS - CCE - PCS - General Science
Vitamins
Which deficiency is more likely in a strict vegan diet without fortified foods or supplements?
A. Vitamin B12 deficiency
B. Vitamin C deficiency
C. Vitamin K deficiency
D. Vitamin E deficiency
Correct Answer: A
A is correct because natural vitamin B12 is primarily found in animal-derived foods, making strict vegans dependent on fortified foods or supplements.
CSS - PMS - CCE - PCS - General Science
Vitamins
Which vitamin deficiency is classically associated with elevated homocysteine plus elevated methylmalonic acid?
A. Vitamin B12
B. Folate
C. Vitamin C
D. Vitamin K
Correct Answer: A
A is correct because B12 deficiency elevates both homocysteine and methylmalonic acid, whereas folate deficiency elevates homocysteine but not methylmalonic acid.
CSS - PMS - CCE - PCS - General Science
Vitamins
Folic acid supplementation can correct the anemia of vitamin B12 deficiency while allowing what complication to progress?
A. Neurologic damage
B. Rickets
C. Scurvy
D. Bleeding from low factor VII
Correct Answer: A
A is correct because folate can improve megaloblastic anemia without correcting B12-related neurologic injury, potentially masking B12 deficiency.
CSS - PMS - CCE - PCS - General Science
Vitamins
Which vitamin deficiency can be triggered by inherited defects in biotinidase, leading to impaired biotin recycling?
A. Biotin (B7)
B. Niacin (B3)
C. Vitamin D
D. Vitamin K
Correct Answer: A
A is correct because biotinidase deficiency impairs recycling of biotin and can cause neurologic and dermatologic manifestations.
CSS - PMS - CCE - PCS - General Science
Vitamins
Which vitamin is required for synthesis of coenzyme A and acyl carrier protein?
A. Pantothenic acid (B5)
B. Folate (B9)
C. Vitamin C
D. Vitamin K
Correct Answer: A
A is correct because pantothenic acid is a structural component of CoA and acyl carrier protein.
CSS - PMS - CCE - PCS - General Science
Vitamins
Which vitamin deficiency may produce glossitis, cheilosis and a magenta tongue?
A. Riboflavin (B2)
B. Vitamin D
C. Vitamin K
D. Vitamin E
Correct Answer: A
A is correct because riboflavin deficiency can produce angular cheilitis, stomatitis, glossitis and a magenta tongue.
CSS - PMS - CCE - PCS - General Science
Vitamins
Transketolase activity depends on:
A. Thiamine pyrophosphate
B. Vitamin K hydroquinone
C. Retinoic acid
D. Alpha-tocopherol
Correct Answer: A
A is correct because transketolase in the pentose phosphate pathway is a TPP-dependent enzyme.
CSS - PMS - CCE - PCS - General Science
Vitamins
Pyruvate dehydrogenase requires which vitamin-derived coenzyme among its cofactors?
A. Thiamine pyrophosphate from B1
B. Retinal from vitamin A
C. Phylloquinone from vitamin K
D. Ascorbate from vitamin C only
Correct Answer: A
A is correct because pyruvate dehydrogenase uses TPP derived from thiamine, along with other cofactors.
CSS - PMS - CCE - PCS - General Science
Vitamins
Which B vitamin-derived coenzyme is used by aminotransferases?
A. Pyridoxal phosphate from B6
B. FAD from B2 only
C. TPP from B1 only
D. THF from B9 only
Correct Answer: A
A is correct because aminotransferases require pyridoxal phosphate, the active form of vitamin B6.
CSS - PMS - CCE - PCS - General Science
Vitamins
Which B vitamin is required for conversion of methylmalonyl-CoA to succinyl-CoA?
A. B12
B. B2
C. B7
D. B9
Correct Answer: A
A is correct because adenosylcobalamin, a B12 coenzyme, is required by methylmalonyl-CoA mutase.
CSS - PMS - CCE - PCS - General Science
Vitamins
Which B vitamin forms the coenzyme tetrahydrofolate, which transfers one-carbon units?
A. B9
B. B1
C. B2
D. B5
Correct Answer: A
A is correct because folate (B9) is reduced to tetrahydrofolate derivatives used in one-carbon metabolism.