Vitamin D analogue (cholecalciferol) Pregnancy: §4.6: should not be used during pregnancy unless the clinical condition of the woman requires treatment with colecalciferol, at a dose necessary to overcome the deficiency; requirements may vary and women should follow the advice of their medical practitioner. Vitamin D overdose during pregnancy causes physical and mental disability and congenital heart and eye conditions in the child, due to hypercalcaemia. Colecalciferol and its metabolites are excreted in breast milk — the practitioner should take account of any maternal dose when prescribing additional vitamin D to a breast-fed child.

Colecalciferol (Vitamin D3)

Brand names: Fultium-D3, Desunin, Invita D3, Stexerol-D3, Aviticol, Pro D3

Used in: Osteoporosis Falls & Frailty

Colecalciferol (vitamin D3) is used to prevent and treat vitamin D deficiency and to support bone health, often alongside calcium.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: Treatment of vitamin D deficiency: 1-4 capsules (1 000-4 000 IU) daily for 10 weeks, followed by maintenance therapy of 1-2 capsules (1 000-2 000 IU) daily

Route: Oral — capsule swallowed whole with water, preferably with the main meal of the day

Frequency: Once daily

eMC §4.2 for 'Colecalciferol 1 000 IU Capsules' (one capsule contains 1 000 IU colecalciferol); this SPC covers the 1 000 IU capsule strength only and does not describe high-dose or intermittent loading regimens. The treatment dose is chosen according to the severity of the disease and the patient's response. Follow-up serum 25(OH)D measurements should be made approximately three to four months after initiating maintenance therapy to confirm that the target level has been achieved. PREVENTION of vitamin D deficiency or TREATMENT of vitamin D insufficiency: 1-2 capsules (1 000-2 000 IU) daily. AS AN ADJUNCT to specific therapy for osteoporosis: 1 capsule (1 000 IU) daily. Higher doses and monitoring of serum 25(OH)D may be required in high-risk groups: institutionalised or hospitalised individuals; dark skinned individuals; those with limited effective sun exposure due to protective clothing or consistent sunscreen use; patients being evaluated for osteoporosis; obese individuals; those on certain concomitant medications (e.g. anticonvulsants, glucocorticoids, antiretrovirals); those recently treated for vitamin D deficiency requiring maintenance; patients with liver or renal disease; and patients with malabsorption including inflammatory bowel disease and coeliac disease. Allowance should be made for vitamin D from supplements, other vitamin D-containing medicines and other sources, and medical supervision is required during treatment to prevent hypercalcaemia. PAEDIATRIC (non-per-kg, so not captured as a structured paediatric dose): adolescents over 12 years, for treatment of vitamin D deficiency or insufficiency — 1 capsule (1 000 IU) daily depending on the severity of the disease and the patient's response, given only under medical supervision. Infants and young children aged 0-12 years: NOT recommended; the product should not be given to infants and children under the age of 12. Verify paediatric use against a children's formulary.

Dose adjustments

Renal

§4.3/§4.4: contraindicated in severe renal impairment. Use with caution in renal impairment, monitoring the effect on calcium and phosphate levels and taking account of the risk of soft tissue calcification; in severe renal insufficiency colecalciferol is not metabolised normally and other forms of vitamin D should be used. Reduce the dose or interrupt treatment if urinary calcium exceeds 7.5 mmol/24 hours (300 mg/24 hours).

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

US labelling (FDA)

Reference — US labelling, may differ from UK

DOSAGE AND ADMINISTRATION: Before, during and/or after pregnancy, one softgel daily or as directed by a physician.

Source: US FDA prescribing information (openFDA / DailyMed), label dated 2024-01-15. Accessed 2026-06-12. US dosing and indications can differ from UK practice — use UK sources for prescribing decisions.

Contraindications

Hypersensitivity to colecalciferol or to any of the excipients
Hypercalcaemia and/or hypercalciuria
Nephrolithiasis (renal calculi)
Hypervitaminosis
Severe renal impairment

Side effects

Hypercalcaemia (uncommon)
Hypercalciuria (uncommon)
Pruritus (rare)
Rash (rare)
Urticaria (rare)

Interactions

Cardiac glycosides (including digitalis) — patients may be susceptible to high calcium levels; monitor ECG parameters and calcium levels
Thiazide diuretics (benzothiadiazine derivatives) — increase the risk of hypercalcaemia by decreasing urinary calcium excretion; monitor plasma and urinary calcium during long-term treatment
Anticonvulsants (phenytoin, phenobarbital, primidone) and rifampicin — may diminish the effect of colecalciferol through hepatic enzyme induction; isoniazid may reduce effectiveness by inhibiting metabolic activation
Drugs causing fat malabsorption (orlistat, liquid paraffin, cholestyramine) — may impair colecalciferol absorption
Vitamin D metabolites or analogues — careful monitoring of serum calcium is recommended if combined; phosphate infusions should not be given to lower the hypercalcaemia of hypervitaminosis D because of the danger of metastatic calcification; actinomycin and imidazole antifungals interfere with vitamin D activity

Clinical monograph

How it works

It is converted in the liver and kidney to active vitamin D (calcitriol), which increases intestinal calcium and phosphate absorption and supports bone mineralisation.

Prescribing in practice

Where deficiency is confirmed, a loading regimen may be used, followed by maintenance.
Excessive intake can cause hypercalcaemia; ensure adequate calcium intake and use caution in conditions that predispose to hypercalcaemia (e.g. sarcoidosis).
It is commonly co-prescribed with bisphosphonates to ensure repletion before/with treatment.

Monitoring

Routine maintenance supplementation usually needs no monitoring; check vitamin D and calcium where high-dose treatment or hypercalcaemia risk applies.

Counselling the patient

Take it regularly; with high-dose treatment follow the schedule provided.
Report symptoms of high calcium such as excessive thirst, frequent urination or constipation.

Evidence & guidelines

Recommended for vitamin D deficiency and as a bone-health adjunct (e.g. with bisphosphonates) per NICE/NOGG guidance.

Reference: NICE PH56 (Vitamin D 2014, updated 2017); NOS Vitamin D & Bone Health 2018; RCPCH Vitamin D Guidance; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Pathways