CDN Pharmacology & Drug-Nutrient Interactions

Question 1

Which antibiotic class chelates divalent cations such as calcium, magnesium, and zinc, significantly reducing their absorption when taken together?

Accepted Answer

Tetracyclines

Answer

Tetracyclines form insoluble complexes with divalent and trivalent cations, impairing both antibiotic and mineral absorption.

Question 2

Patients on warfarin (Coumadin) anticoagulation therapy require careful monitoring of their intake of which vitamin?

Accepted Answer

Vitamin K

Answer

Vitamin K is essential for the synthesis of clotting factors II, VII, IX, and X; fluctuating intake directly affects warfarin's anticoagulant effect.

Question 3

Long-term use of proton pump inhibitors (PPIs) most commonly leads to clinically significant deficiency of which nutrient?

Accepted Answer

Vitamin B12

Answer

PPIs suppress gastric acid, which is required to cleave vitamin B12 from dietary protein and for intrinsic factor–mediated absorption.

Question 4

Metformin, a first-line medication for type 2 diabetes, is associated with reduced absorption of which vitamin over time?

Accepted Answer

Vitamin B12

Answer

Metformin interferes with calcium-dependent absorption of the vitamin B12–intrinsic factor complex in the terminal ileum.

Question 5

Which beverage most significantly interacts with statin medications by inhibiting CYP3A4 and increasing the risk of myopathy?

Accepted Answer

Grapefruit juice

Answer

Grapefruit juice contains furanocoumarins that irreversibly inhibit intestinal CYP3A4, dramatically increasing statin plasma levels and toxicity risk.

(CDN) Certified Dietician Nutritionist Practice Test

(CDN) Certified Dietician Nutritionist Practice Test

CDN Pharmacology & Drug-Nutrient Interactions