CSR Bone and Mineral Metabolism in CKD (CKD-MBD) 3

Question 1

What term describes the systemic disorder in CKD encompassing abnormalities of calcium, phosphorus, PTH, and vitamin D metabolism along with bone disease and vascular calcification?

Accepted Answer

CKD-Mineral and Bone Disorder (CKD-MBD)

Answer

Secondary hyperparathyroidism

Answer

Renal osteodystrophy

Answer

Osteoporosis of renal origin

Question 2

Which laboratory value is the BEST indicator of nutritional (storage) vitamin D status in a CKD patient, and should be checked before starting supplementation?

Accepted Answer

Serum 25-hydroxyvitamin D (calcidiol) level

Answer

Serum calcitriol (1,25-dihydroxyvitamin D) level

Answer

Serum PTH level alone

Answer

Alkaline phosphatase level

Question 3

A CKD G4 patient develops vascular calcification on imaging. Which phosphate management strategy is MOST appropriate according to current guidelines?

Accepted Answer

Prioritize dietary phosphorus restriction and use calcium-free phosphate binders when needed

Answer

Increase calcium carbonate dose to maximize phosphate binding

Answer

Prescribe high-dose calcitriol to suppress PTH-driven calcification

Answer

Restrict protein intake to below 0.6 g/kg/day to reduce endogenous phosphorus

Question 4

Tertiary hyperparathyroidism most commonly develops in which clinical scenario?

Accepted Answer

After kidney transplantation when autonomous parathyroid hyperplasia persists despite restored renal function

Answer

Early CKD G2 when phosphorus first begins to rise

Answer

During acute kidney injury

Answer

After starting a plant-based diet

Question 5

Klotho, a co-receptor for FGF-23, declines progressively in CKD. What is the PRIMARY consequence of reduced Klotho expression?

Accepted Answer

Impaired FGF-23 signaling leading to phosphate retention and decreased calcitriol synthesis

Answer

Elevated serum calcium due to increased gut absorption

Answer

Suppressed PTH secretion from the parathyroid gland

Answer

Increased bone mineral density due to reduced osteoclast activity

Question 6

A renal dietitian counsels a hemodialysis patient on the 'phosphorus protein ratio' approach. Which combination BEST represents a high-phosphorus-to-protein ratio food to LIMIT?

Accepted Answer

Processed cheese and cola beverages

Answer

Egg whites and fresh fish

Answer

Chicken breast and tofu

Answer

Unsalted nuts and fresh vegetables

Question 7

Per KDIGO 2017 recommendations, what is the suggested upper limit for total elemental calcium intake (diet plus supplements) in most adult CKD patients to reduce the risk of hypercalcemia and vascular calcification?

Accepted Answer

2,000 mg/day

Answer

500 mg/day

Answer

1,000 mg/day

Answer

3,500 mg/day