What role do vitamin D supplements play in the management of CKD-MBD, and what are the guidelines for their use in different stages of CKD?

Role of Vitamin D Supplements in CKD-MBD Management: Vitamin D supplements are used primarily to treat vitamin D deficiency in people with chronic kidney disease (CKD) who have confirmed deficiency. They are not routinely offered to manage or prevent CKD-mineral and bone disorder (CKD-MBD) unless deficiency is present.

For people with CKD and vitamin D deficiency, colecalciferol or ergocalciferol should be offered to correct the deficiency.

If vitamin D deficiency has been corrected but symptoms of CKD-MBD persist, active vitamin D analogues such as alfacalcidol (1-alpha-hydroxycholecalciferol) or calcitriol (1,25-dihydroxycholecalciferol) may be offered to people with a glomerular filtration rate (GFR) less than 30 ml/min/1.73 m² (CKD stages G4 or G5).

Serum calcium and phosphate concentrations should be monitored in people receiving alfacalcidol or calcitriol supplements to avoid complications.

Current Guidelines Across CKD Stages:

• In CKD stages G1 to G3 (GFR ≥30 ml/min/1.73 m²), routine measurement of calcium, phosphate, parathyroid hormone (PTH), and vitamin D levels is not recommended, and vitamin D supplementation is not routinely offered for CKD-MBD management.
• In CKD stages G4 and G5 (GFR <30 ml/min/1.73 m²), serum calcium, phosphate, and PTH concentrations should be measured, and if vitamin D deficiency is present, supplementation with colecalciferol or ergocalciferol is recommended.
• If CKD-MBD symptoms persist after correcting vitamin D deficiency in stages G4 and G5, active vitamin D analogues (alfacalcidol or calcitriol) may be used with careful monitoring.

For detailed management of CKD-MBD beyond vitamin D supplementation, specialist renal advice should be sought.

Summary: Vitamin D supplementation in CKD-MBD is targeted to correcting deficiency first, with active vitamin D analogues reserved for advanced CKD (G4/G5) if symptoms persist after correction. Routine supplementation without deficiency is not recommended.

All recommendations are based on NICE guideline NG203: Chronic kidney disease: assessment and management ¹.