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Calcium and Vitamin D Supplement Pregnancy: §4.6 Pregnancy: 'Calcichew-D3 Forte Chewable Tablets can be used during pregnancy, in case of a calcium and vitamin D deficiency. During pregnancy the daily intake should not exceed 2500 mg calcium and 4000 IU vitamin D. Studies in animals have shown reproductive toxicity with high doses of vitamin D… In pregnant women, overdoses of calcium and vitamin D should be avoided as permanent hypercalcaemia has been related to adverse effects on the developing foetus. There are no indications that vitamin D at therapeutic doses is teratogenic in humans.' Lactation: 'Calcichew-D3 Forte Chewable Tablets can be used during breast-feeding. Calcium and vitamin D3 pass into breast milk. This should be considered when giving additional vitamin D to the child.'

Calcium 1000mg + Colecalciferol 800 units (Calcichew D3 Forte)

Brand names: Calcichew D3 Forte, Adcal-D3, Calfovit D3

Used in: Falls & Frailty

This is a fixed-dose calcium carbonate and colecalciferol (vitamin D3) chewable combination used as an adjunct to osteoporosis therapy and to correct or prevent combined calcium and vitamin D deficiency, frequently alongside a bisphosphonate after fragility fracture.

Adult dose

Dose: One chewable tablet of Calcichew-D3 Forte 500 mg/400 IU (calcium 500 mg with colecalciferol 400 IU per tablet)
Route: Oral — §4.2 Method of Administration: 'Oral. The tablets should be chewed or sucked.'
Frequency: Twice daily
Verbatim posology: 'Adults and elderly: Adjunctive therapy in osteoporosis and Calcium and vitamin D deficiency One tablet twice daily.' The tablet count is quantified by the SPC product name, 'Calcichew-D3 Forte 500 mg/400 IU Chewable Tablets', which is where the per-tablet 500 mg calcium / 400 IU colecalciferol figures come from; the §2 qualitative and quantitative composition statement was not included in the fetched bundle. DAILY TOTAL (arithmetic, not a figure printed in the SPC): two tablets a day deliver 1000 mg calcium and 800 IU colecalciferol in total (2 × 500 mg and 2 × 400 IU) — that is the daily total quoted in this page's title. maxDose is left blank on purpose: the SPC states no general daily ceiling for this product. The only numeric ceiling anywhere in the fetched text is pregnancy-specific — §4.6: 'During pregnancy the daily intake should not exceed 2500 mg calcium and 4000 IU vitamin D' — which is a subgroup rule, not a ceiling on the dose shown, so it is recorded in the pregnancy field instead. Dose reduction rule (§4.4): 'In case of hypercalcaemia or signs of impaired renal function the dose should be reduced or the treatment discontinued.' Cautions (§4.4): use with caution in hypercalcaemia or signs of impaired renal function, 'The risk of soft tissue calcification should be taken into account'; caution in sarcoidosis 'because of the risk of increased metabolism of vitamin D3 to its active form'; caution 'in immobilised patients with osteoporosis due to the increased risk of hypercalcaemia'; with other high-dose vitamin D and/or calcium-containing medicines or foods (such as milk) 'there is a risk of hypercalcaemia and milk-alkali syndrome with subsequent kidney function impairment'. Excipients (§4.4): 'Calcichew-D3 Forte Chewable Tablets contain isomalt (E953) and sucrose. Patients with rare hereditary problems of fructose intolerance, glucose-galactose malabsorption or sucrase-isomaltase insufficiency should not take this medicine.' Separation from other drugs (§4.5): tetracyclines 'should be administered at least two hours before, or four to six hours after, oral intake of calcium carbonate'; 'Administration of calcium and levothyroxine should be separated by at least four hours'; quinolone absorption may also be impaired.

Dose adjustments

Renal

§4.2 Impaired renal function: 'Calcichew-D3 Forte Chewable Tablets should not be used in patients with severe renal impairment (see section 4.3).' §4.3 defines that as a contraindication: 'Severe renal impairment (glomerular filtration rate < 30 ml/min)'. §4.4 adds: 'In patients with severe renal insufficiency, vitamin D in the form of colecalciferol is not metabolised normally and other forms of vitamin D should be used', that the product 'should be used with caution in patients with… signs of impaired renal function and the effect on calcium and phosphate levels should be monitored', and that 'In case of hypercalcaemia or signs of impaired renal function the dose should be reduced or the treatment discontinued.' No graded dose reduction is given.

Hepatic

§4.2 Impaired hepatic function: 'No dose adjustment is required.'

Dose independently re-sourced from UK Summary of Product Characteristics (SPC) via the eMC — clinician-reviewed. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

  • Hypersensitivity to the active substances or to any of the excipients listed in section 6.1 (§4.3)
  • Diseases and/or conditions resulting in hypercalcaemia and/or hypercalciuria (§4.3)
  • Severe renal impairment (glomerular filtration rate < 30 ml/min) (§4.3)
  • Renal calculi (nephrolithiasis) (§4.3)
  • Hypervitaminosis D (§4.3)
  • Not a §4.3 item but a formulation bar (§4.4): patients with rare hereditary problems of fructose intolerance, glucose-galactose malabsorption or sucrase-isomaltase insufficiency 'should not take this medicine' (the tablets contain isomalt and sucrose)

Side effects

  • Metabolism — uncommon (≥1/1,000 to <1/100): hypercalcaemia and hypercalciuria (§4.8)
  • Metabolism — very rare (≤1/10,000): 'Milk-alkali syndrome (frequent urge to urinate; continuing headache; continuing loss of appetite; nausea or vomiting; unusual tiredness or weakness; hypercalcaemia, alkalosis and renal impairment). Seen usually only in overdose'
  • Gastrointestinal — rare (≥1/10,000 to <1/1,000): constipation, dyspepsia, flatulence, nausea, abdominal pain and diarrhoea (§4.8)
  • Skin and subcutaneous — rare: pruritus, rash and urticaria (§4.8)
  • Immune system — frequency not known: 'Hypersensitivity reactions such as angio-oedema or laryngeal oedema' (§4.8)

Monitoring

  • Long-term treatment (§4.4): 'During long-term treatment, serum calcium levels should be followed and renal function should be monitored through measurements of serum creatinine.'
  • Higher-risk groups (§4.4): monitoring 'is especially important in patients on concomitant treatment with cardiac glycosides or diuretics… and in patients with a high tendency to calculus formation'
  • Thiazide diuretics (§4.5): 'Thiazide diuretics reduce the urinary excretion of calcium. Due to increased risk of hypercalcaemia, serum calcium should be regularly monitored during concomitant use of thiazide diuretics.'
  • Cardiac glycosides (§4.5): 'Hypercalcaemia may increase the toxicity of cardiac glycosides during treatment with calcium and vitamin D. Patients should be monitored with regard to electrocardiogram (ECG) and serum calcium levels.'
  • Sarcoidosis (§4.4): 'These patients should be monitored with regard to the calcium content in serum and urine.'
  • Concomitant high-dose vitamin D or calcium-containing medicines/nutrients (§4.4): 'In these patients serum calcium levels should be followed and renal function should be monitored.'
  • Impaired renal function or hypercalcaemia (§4.4): 'the effect on calcium and phosphate levels should be monitored'

Clinical monograph

How it works

Colecalciferol is converted to active vitamin D metabolites that promote intestinal calcium absorption, while the supplied calcium provides substrate for bone mineralisation and helps suppress secondary hyperparathyroidism.

Prescribing in practice

  • Avoid in hypercalcaemia, hypercalciuria and conditions predisposing to calcium-containing stones, and use caution in renal impairment and sarcoidosis where vitamin D sensitivity is increased.
  • Separate administration from oral bisphosphonates, levothyroxine, iron and certain antibiotics, as the calcium reduces their absorption.
  • Thiazide diuretics increase the risk of hypercalcaemia when combined.

Monitoring

Monitor serum and urinary calcium and renal function periodically, particularly in those with impaired renal function or on interacting drugs.

Counselling the patient

  • Chew the tablet well; take it at a different time of day from a bisphosphonate, thyroid tablets or iron.
  • Report symptoms such as nausea, constipation, excessive thirst or passing large amounts of urine, which may indicate high calcium.

Evidence & guidelines

Combined calcium and vitamin D supplementation is recommended adjunctive therapy in osteoporosis management, including in NICE fragility-fracture guidance.

Reference: NOGG Osteoporosis Guidelines 2021; NICE TA160; NICE TA161; 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).

Related

Curated clinical cross-links plus same-class fallbacks.

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