Chronic kidney disease — mineral and bone disorder

Red Flags

Severe hypercalcaemia (corrected Ca >12 mg/dL or symptomatic) — stop calcium-based binders and active vitamin D, IV saline, consider cinacalcet/calcimimetic; admit if symptomatic^[1]
Calciphylaxis (painful necrotic skin lesions on lower abdomen, thighs, calves in dialysis patients) — emergent multidisciplinary referral; nephrology, dermatology, pain, wound care; sodium thiosulfate^[1]
PTH >9× upper limit of normal in CKD G5D unresponsive to medical therapy — parathyroidectomy evaluation^[1]
Symptomatic hyperphosphataemia with vascular calcification or pruritus — phosphate binder + dietary phosphate restriction; non-calcium binder preferred^[1]

First-line treatment

Interventions

Dietary phosphate restriction^[1]
Limit processed foods and additives (inorganic phosphate has high bioavailability); plant-based protein has lower phosphate absorption; renal dietitian co-management
Treat hyperphosphataemia toward normal range^[1]
In CKD G3a–G5D treat overt hyperphosphataemia rather than chase any specific target; avoid hypercalcaemia and over-suppression of PTH
Parathyroidectomy^[1]
CKD G3a–G5D with severe secondary or tertiary hyperparathyroidism refractory to medical therapy; subtotal or total with autotransplant; manage post-op hungry bone syndrome

First-line drug therapy

Drug	Class	Adult	Paediatric	Notes
Sevelamer carbonate^[1]	Non-calcium phosphate binder (anion-exchange polymer)	800–1600 mg PO TDS with meals; titrate to phosphate	—	Preferred in vascular calcification, hypercalcaemia, or low PTH; reduces calcium load vs calcium binders
Lanthanum carbonate^[1]	Non-calcium phosphate binder	500–1000 mg PO TDS with meals (chew); max 3000 mg/day	—	Non-calcium binder; chewable; avoid in pregnancy; long-term tissue accumulation noted but clinical significance unclear
Calcium acetate or calcium carbonate^[1]	Calcium-based phosphate binder	Calcium acetate 667–1334 mg PO TDS with meals; calcium carbonate 500–1500 mg PO TDS with meals	—	Restrict in adynamic bone disease, hypercalcaemia, vascular calcification; calcium acetate has lower calcium load per unit phosphate binding than carbonate
Calcitriol or alfacalcidol^[1]	Active vitamin D / 1-alpha hydroxylated analogue	Calcitriol 0.25–0.5 µg PO daily or 1–2 µg IV thrice weekly with HD; alfacalcidol 0.25–1 µg PO daily	—	Severe and progressive secondary hyperparathyroidism in CKD G4–G5D; not routine for elevated PTH alone in G3a–G4
Cinacalcet^[1]	Calcimimetic (calcium-sensing receptor agonist)	30 mg PO once daily; titrate to PTH target every 4 weeks; max 180 mg/day	—	Secondary hyperparathyroidism in CKD G5D with PTH above target despite vitamin D analogue; hypocalcaemia is dose-limiting
Etelcalcetide^[1]	Intravenous calcimimetic	5 mg IV at end of haemodialysis thrice weekly; titrate by 2.5–5 mg increments	—	Alternative to oral cinacalcet in HD patients with adherence concerns; hypocalcaemia and QT prolongation

Sevelamer carbonate^[1]

Non-calcium phosphate binder (anion-exchange polymer)

Adult: 800–1600 mg PO TDS with meals; titrate to phosphate
Paediatric: —

Preferred in vascular calcification, hypercalcaemia, or low PTH; reduces calcium load vs calcium binders

Lanthanum carbonate^[1]

Non-calcium phosphate binder

Adult: 500–1000 mg PO TDS with meals (chew); max 3000 mg/day
Paediatric: —

Non-calcium binder; chewable; avoid in pregnancy; long-term tissue accumulation noted but clinical significance unclear

Calcium acetate or calcium carbonate^[1]

Calcium-based phosphate binder

Adult: Calcium acetate 667–1334 mg PO TDS with meals; calcium carbonate 500–1500 mg PO TDS with meals
Paediatric: —

Restrict in adynamic bone disease, hypercalcaemia, vascular calcification; calcium acetate has lower calcium load per unit phosphate binding than carbonate

Calcitriol or alfacalcidol^[1]

Active vitamin D / 1-alpha hydroxylated analogue

Adult: Calcitriol 0.25–0.5 µg PO daily or 1–2 µg IV thrice weekly with HD; alfacalcidol 0.25–1 µg PO daily
Paediatric: —

Severe and progressive secondary hyperparathyroidism in CKD G4–G5D; not routine for elevated PTH alone in G3a–G4

Cinacalcet^[1]

Calcimimetic (calcium-sensing receptor agonist)

Adult: 30 mg PO once daily; titrate to PTH target every 4 weeks; max 180 mg/day
Paediatric: —

Secondary hyperparathyroidism in CKD G5D with PTH above target despite vitamin D analogue; hypocalcaemia is dose-limiting

Etelcalcetide^[1]

Intravenous calcimimetic

Adult: 5 mg IV at end of haemodialysis thrice weekly; titrate by 2.5–5 mg increments
Paediatric: —

Alternative to oral cinacalcet in HD patients with adherence concerns; hypocalcaemia and QT prolongation

Safety-net

Avoid over-the-counter calcium and high-dose vitamin D supplements unless prescribed — in CKD they cause hypercalcaemia and accelerate vascular calcification^[1]
Painful purple skin patches on the abdomen, thighs, or calves while on dialysis — same-day call to nephrology (concern for calciphylaxis)^[1]
Take phosphate binders with meals, not separately — they only work when bound to food phosphate in the gut^[1]

Referral criteria

Severe or symptomatic hypercalcaemia, calciphylaxis, or PTH >9× ULN despite medical therapyNephrology and consider parathyroid surgery^[1]
Persistent hyperphosphataemia despite dietary restriction and adequate dialysisNephrology with phosphate binder optimisation^[1]
Fragility fracture or DXA T-score ≤-2.5 in CKD G3a–G5DNephrology and bone-health specialist; bone biopsy may be needed before antiresorptive therapy^[1]

Clinical summary

Diagnosis and management of disordered calcium, phosphate, PTH, vitamin D, and bone in CKD G3a–G5D, including dialysis vintage.

References

1.KDIGO 2017 Clinical Practice Guideline Update for CKD-MBD; KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of CKD (calcium/phosphate trends) (2017)