CSS - PMS - CCE - PCS - General Science
Vitamins
The active coenzyme form of thiamine is:
A. Thiamine pyrophosphate (TPP)
B. FAD
C. NAD+
D. Pyridoxal phosphate
Correct Answer: A
A is correct. TPP is the active coenzyme form of thiamine and participates in oxidative decarboxylation and transketolase reactions.
CSS - PMS - CCE - PCS - General Science
Vitamins
Vitamin B1 is commonly known as:
A. Thiamine
B. Riboflavin
C. Niacin
D. Pyridoxine
Correct Answer: A
A is correct. Vitamin B1 is thiamine.
CSS - PMS - CCE - PCS - General Science
Vitamins
Warfarin exerts its anticoagulant effect mainly by antagonizing:
A. Vitamin K recycling
B. Vitamin C absorption
C. Vitamin B12 binding
D. Vitamin E synthesis
Correct Answer: A
A is correct because warfarin inhibits vitamin K epoxide reductase, reducing activation of vitamin K-dependent clotting factors.
CSS - PMS - CCE - PCS - General Science
Vitamins
Which clotting factor is NOT vitamin K dependent?
A. Factor V
B. Factor II
C. Factor VII
D. Factor IX
Correct Answer: A
A is correct. Vitamin K-dependent coagulation factors include II, VII, IX and X, as well as proteins C and S; factor V is not vitamin K dependent.
CSS - PMS - CCE - PCS - General Science
Vitamins
A newborn is routinely given vitamin K mainly to prevent:
A. Vitamin K deficiency bleeding
B. Rickets
C. Scurvy
D. Pellagra
Correct Answer: A
A is correct because newborns have low vitamin K stores and limited intestinal bacterial production, increasing risk of bleeding.
CSS - PMS - CCE - PCS - General Science
Vitamins
Vitamin K2 is collectively known as:
A. Menaquinones
B. Tocopherols
C. Retinoids
D. Calciferols
Correct Answer: A
A is correct because vitamin K2 refers to a family of menaquinones produced by bacteria and found in some fermented foods.
CSS - PMS - CCE - PCS - General Science
Vitamins
Vitamin K1 is known as:
A. Phylloquinone
B. Menaquinone
C. Menadione
D. Thiamine
Correct Answer: A
A is correct. Phylloquinone is vitamin K1 and is abundant in green leafy vegetables.
CSS - PMS - CCE - PCS - General Science
Vitamins
Vitamin K is required for gamma-carboxylation of certain proteins involved mainly in:
A. Coagulation and bone metabolism
B. DNA base pairing
C. Glycogen digestion
D. Thyroid hormone synthesis
Correct Answer: A
A is correct because vitamin K is a cofactor for gamma-glutamyl carboxylase, which activates several clotting factors and bone proteins.
CSS - PMS - CCE - PCS - General Science
Vitamins
Which food group is generally a good source of vitamin E?
A. Vegetable oils, nuts and seeds
B. Refined sugar only
C. Table salt
D. Distilled water
Correct Answer: A
A is correct because plant oils, nuts and seeds are important dietary sources of tocopherols.
CSS - PMS - CCE - PCS - General Science
Vitamins
Vitamin E deficiency is most likely to cause which problem in severe cases?
A. Neuromuscular dysfunction and hemolysis
B. Goitre
C. Scurvy
D. Megaloblastic anemia from folate deficiency
Correct Answer: A
A is correct because vitamin E deficiency can cause peripheral neuropathy, ataxia and hemolytic anemia, especially in fat-malabsorption states.
CSS - PMS - CCE - PCS - General Science
Vitamins
The most biologically active form of vitamin E in humans is:
A. Alpha-tocopherol
B. Ergocalciferol
C. Phylloquinone
D. Riboflavin
Correct Answer: A
A is correct because alpha-tocopherol is the principal biologically active form of vitamin E in humans.
CSS - PMS - CCE - PCS - General Science
Vitamins
Which vitamin primarily protects cell membranes from oxidative damage?
A. Vitamin E
B. Vitamin K
C. Vitamin B1
D. Vitamin B9
Correct Answer: A
A is correct because vitamin E is a major lipid-soluble antioxidant that protects polyunsaturated fatty acids in membranes from oxidation.
CSS - PMS - CCE - PCS - General Science
Vitamins
Excess vitamin D can lead to:
A. Hypercalcemia
B. Severe hypoglycemia
C. Scurvy
D. Night blindness
Correct Answer: A
A is correct because vitamin D toxicity increases calcium absorption and may cause hypercalcemia, nephrocalcinosis and related complications.
CSS - PMS - CCE - PCS - General Science
Vitamins
Vitamin D deficiency in adults may cause:
A. Osteomalacia
B. Scurvy
C. Pellagra
D. Beriberi
Correct Answer: A
A is correct because inadequate vitamin D in adults causes defective bone mineralization called osteomalacia.
CSS - PMS - CCE - PCS - General Science
Vitamins
The main intestinal effect of vitamin D is to increase absorption of:
A. Calcium and phosphate
B. Sodium and chloride only
C. Iron only
D. Vitamin C only
Correct Answer: A
A is correct because vitamin D increases intestinal absorption of calcium and phosphate, supporting bone mineralization.
CSS - PMS - CCE - PCS - General Science
Vitamins
Final activation of vitamin D to calcitriol occurs mainly in the:
A. Kidney
B. Stomach
C. Spleen
D. Colon
Correct Answer: A
A is correct because renal 1-alpha-hydroxylase converts calcidiol to calcitriol.
CSS - PMS - CCE - PCS - General Science
Vitamins
The hormonally active form of vitamin D is:
A. Calcitriol
B. Calcidiol
C. Cholecalciferol
D. Ergocalciferol
Correct Answer: A
A is correct. Calcitriol is 1,25-dihydroxyvitamin D, the active hormone-like form produced mainly in the kidney.
CSS - PMS - CCE - PCS - General Science
Vitamins
The major circulating storage form used to assess vitamin D status is:
A. 25-hydroxyvitamin D (calcidiol)
B. 1,25-dihydroxyvitamin D only
C. 7-dehydrocholesterol
D. Ergosterol
Correct Answer: A
A is correct because serum 25-hydroxyvitamin D is the standard marker of body vitamin D status. Calcitriol is tightly regulated and is not the best routine measure of stores.
CSS - PMS - CCE - PCS - General Science
Vitamins
Vitamin D2 is also called:
A. Ergocalciferol
B. Cholecalciferol
C. Calcidiol
D. Phylloquinone
Correct Answer: A
A is correct. Ergocalciferol is vitamin D2, commonly derived from fungal or plant sterols.
CSS - PMS - CCE - PCS - General Science
Vitamins
The form of vitamin D3 is known as:
A. Cholecalciferol
B. Ergocalciferol
C. Calcitriol
D. Retinal
Correct Answer: A
A is correct. Vitamin D3 is cholecalciferol; vitamin D2 is ergocalciferol.