Question

Question 1: Nutrients can affect the actions of drugs, and drugs can affect nutrient absorption, metabolism and excretion. Describe a specific instance in which diet can affect drug absorption. Explain how the drug works, the nutrient-drug interaction and potential consequences of this interaction.

Marie is 65 years old and overall has a very healthy diet. Marie avoids dairy because it upsets her stomach and drinks calcium fortified orange juice and chooses calcium-rich vegetables because she knows that she needs calcium to protect her bones. She also dislikes fish, with chicken providing most of her protein. Lab results from Marie’s annual physical showed that her serum vitamin D levels are very low. Marie’s doctor has suggested that she take a vitamin D supplement to bring those levels up. Marie hates taking pills and wonders why that’s necessary when she spends a lot of time outdoors gardening.

Question 2: Explain why Marie’s serum vitamin D levels are low despite the time she spends gardening.

Answer 1

Vitamin D supplements :-

#. Mechanism of action of vitamin D

Active vitamin D will bind to specific receptor VDR ''vitamin D receptor" in target tissues and exert it's metabolic action.

1,25 DHCC has 3 times more affinity to these receptor than other vitamin D metabolites

#. Nutrient- drug interaction :-

- Calcipotriene (Dovonex) interacts with VITAMIN D

Calcipotriene is a drug that is similar to vitamin D. Taking vitamin D along with calcipotriene (Dovonex) might increase the effects and side effects of calcipotriene (Dovonex). Avoid taking vitamin D supplements if you are taking calcipotriene (Dovonex).

- Digoxin (Lanoxin) interacts with VITAMIN D

Vitamin D helps your body absorb calcium. Calcium can affect the heart. Digoxin (Lanoxin) is used to help your heart beat stronger. Taking vitamin D along with digoxin (Lanoxin) might increase the effects of digoxin (Lanoxin) and lead to an irregular heartbeat. If you are taking digoxin (Lanoxin), talk to your doctor before taking vitamin D supplements.

- Diltiazem (Cardizem, Dilacor, Tiazac) interacts with VITAMIN D

Vitamin D helps your body absorb calcium. Calcium can affect your heart. Diltiazem (Cardizem, Dilacor, Tiazac) can also affect your heart. Taking large amounts of vitamin D along with diltiazem (Cardizem, Dilacor, Tiazac) might decrease the effectiveness of diltiazem.

- Verapamil (Calan, Covera, Isoptin, Verelan) interacts with VITAMIN D

Vitamin D helps your body absorb calcium. Calcium can affect the heart. Verapamil (Calan, Covera, Isoptin, Verelan) can also affect the heart. Do not take large amounts of vitamin D if you are taking verapamil (Calan, Covera, Isoptin, Verelan).

#. Marie's vitamin D would be low because she don't consume enough or absorb enough from food, her exposure to sunlight might be limited, or her kidneys cannot convert vitamin D to its active form in the body.