CDN Renal & Cardiac Nutrition 5 — Questions and Answers
Question 1: A dietitian reviews a cardiac patient's lab results showing homocysteine of 18 µmol/L. Which B-vitamin combination most directly addresses elevated homocysteine?
- Thiamin, riboflavin, and niacin
- Folate, B6, and B12 (Correct answer)
- Biotin and pantothenic acid
- B12 and thiamin only
Correct answer: Folate, B6, and B12
Folate, B6, and B12 are co-factors in homocysteine metabolism; deficiency of any raises homocysteine, increasing cardiovascular risk.
Question 2: A patient with polycystic kidney disease (PKD) asks about diet. Which intervention has the strongest emerging evidence for slowing PKD progression?
- High-protein diet
- Calorie restriction or time-restricted eating to reduce mTOR activity (Correct answer)
- High-fat ketogenic diet
- Gluten-free diet
Correct answer: Calorie restriction or time-restricted eating to reduce mTOR activity
Emerging research supports caloric restriction and time-restricted eating as strategies to inhibit mTOR signaling, which drives cyst growth in PKD.
Question 3: What is the recommended eicosapentaenoic acid plus docosahexaenoic acid (EPA+DHA) intake per day for a patient with established coronary heart disease?
- 250 mg/day
- 500 mg/day
- 1,000 mg/day or more (Correct answer)
- 100 mg/day
Correct answer: 1,000 mg/day or more
AHA recommends at least 1 g/day of EPA+DHA from fish or supplements for patients with documented coronary heart disease.
Question 4: A dialysis patient's nPCR (normalized protein catabolic rate) is 0.7 g/kg/day. What does this indicate?
- Adequate protein intake
- Protein intake above target
- Inadequate dietary protein intake (Correct answer)
- Normal anabolism
Correct answer: Inadequate dietary protein intake
An nPCR below 1.0-1.2 g/kg/day for dialysis patients indicates inadequate protein intake, putting the patient at risk for protein-energy wasting.
Question 5: Which dietary pattern most effectively reduces LDL cholesterol through a mechanism involving increased bile acid excretion?
- High saturated fat diet
- High soluble fiber diet (oats, barley, psyllium) (Correct answer)
- High protein diet
- Low carbohydrate, high fat diet
Correct answer: High soluble fiber diet (oats, barley, psyllium)
Soluble fiber binds bile acids in the gut, promoting fecal excretion and forcing the liver to convert more cholesterol to bile acids, lowering serum LDL.
Question 6: A CKD patient on a phosphate binder is prescribed calcium carbonate. When should this be taken to maximize its phosphate-binding effect?
- At bedtime on an empty stomach
- First thing in the morning before breakfast
- With meals and snacks (Correct answer)
- Two hours after meals
Correct answer: With meals and snacks
Calcium carbonate phosphate binders must be taken with meals and snacks to bind dietary phosphorus in the GI tract before absorption.
Question 7: A patient with both CKD stage 4 and heart failure requires fluid restriction. Which fluid restriction target best balances both conditions?
- Unrestricted fluids
- 3 liters per day
- 1,500-2,000 mL/day adjusted for urine output and symptoms (Correct answer)
- 500 mL/day
Correct answer: 1,500-2,000 mL/day adjusted for urine output and symptoms
For CKD with comorbid heart failure, fluid restriction of 1,500-2,000 mL/day (adjusted for residual urine output and edema status) balances both conditions.
CDN Renal & Cardiac Nutrition 5
A dietitian reviews a cardiac patient's lab results showing homocysteine of 18 µmol/L.
Which B-vitamin combination most directly addresses elevated homocysteine?