CSS - PMS - CCE - PCS - General Science
Vitamins
Smokers generally have higher requirements for which vitamin because oxidative stress accelerates its turnover?
A. Vitamin C
B. Vitamin K
C. Vitamin B12
D. Vitamin D only
Correct Answer: A
A is correct because smoking increases oxidative stress and lowers vitamin C concentrations, increasing dietary requirements.
CSS - PMS - CCE - PCS - General Science
Vitamins
Which symptom combination most strongly suggests scurvy?
A. Bleeding gums, bruising and poor wound healing
B. Night blindness and dry eyes
C. Bone bowing in a child
D. Dermatitis, diarrhea and dementia
Correct Answer: A
A is correct because scurvy causes capillary fragility, gingival disease and impaired wound healing due to defective collagen.
CSS - PMS - CCE - PCS - General Science
Vitamins
Which vitamin deficiency is especially associated with perifollicular hemorrhages and corkscrew hairs?
A. Vitamin C
B. Vitamin A
C. Vitamin B1
D. Vitamin D
Correct Answer: A
A is correct because fragile connective tissue in scurvy can produce perifollicular bleeding and corkscrew hairs.
CSS - PMS - CCE - PCS - General Science
Vitamins
Vitamin C can help regenerate oxidized:
A. Vitamin E
B. Vitamin K only
C. Vitamin D
D. Vitamin B12
Correct Answer: A
A is correct because ascorbate participates in antioxidant networks and can help regenerate tocopherol from its oxidized radical form.
CSS - PMS - CCE - PCS - General Science
Vitamins
Which vitamin is a major chain-breaking antioxidant in lipid membranes?
A. Vitamin E
B. Vitamin C only
C. Vitamin B12
D. Vitamin K
Correct Answer: A
A is correct because alpha-tocopherol interrupts lipid peroxidation chain reactions in biological membranes.
CSS - PMS - CCE - PCS - General Science
Vitamins
Which vitamin deficiency may cause hemolytic anemia in premature infants because of oxidative membrane damage?
A. Vitamin E
B. Vitamin A
C. Vitamin B1
D. Vitamin D
Correct Answer: A
A is correct because vitamin E protects erythrocyte membranes from oxidative injury; deficiency can contribute to hemolysis.
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.