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Vitamin D Supplement (Native Vitamin D3)

Colecalciferol 1000–2000 units/day

Brand names: InVita D3, Fultium-D3, Thorens (high-dose)

Used in: Falls & Frailty

Colecalciferol (vitamin D3) at a maintenance daily dose is used to correct and prevent vitamin D deficiency in chronic kidney disease, supporting bone health as part of CKD-mineral and bone disorder management.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

Clinical monograph

How it works

Colecalciferol is converted in the liver to 25-hydroxyvitamin D and then in the kidney to active 1,25-dihydroxyvitamin D, which promotes intestinal calcium and phosphate absorption and supports bone mineralisation.

Prescribing in practice

  • In advanced CKD renal activation of vitamin D is impaired, so colecalciferol replenishes nutritional stores but an active vitamin D analogue (e.g. alfacalcidol) may be needed for the endocrine effect; avoid in hypercalcaemia.
  • Excessive intake causes hypercalcaemia and hyperphosphataemia, which is hazardous in CKD and can worsen vascular calcification.
  • Many combination products contain calcium; the plain colecalciferol-only preparation avoids an additional calcium load in patients already on calcium-based binders.

Monitoring

Monitor serum calcium and phosphate, with vitamin D and parathyroid hormone levels as part of CKD-MBD review.

Counselling the patient

  • This replaces vitamin D to support your bones; take it regularly as prescribed.
  • Do not take additional high-dose vitamin D or calcium supplements without advice.
  • Report symptoms of high calcium such as thirst, frequent urination, nausea or confusion.

Evidence & guidelines

Correcting vitamin D deficiency is recommended within CKD-MBD guidance (NICE/KDIGO), with active vitamin D reserved for treating secondary hyperparathyroidism.

Reference: KDIGO CKD-MBD Guidelines 2017; NICE NG203; NICE CG71 (Vitamin D deficiency); Confirm identity and dosing against the manufacturer SPC (eMC) and NICE. Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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