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Calcium supplement Pregnancy: 'There is epidemiological evidence of the safety of calcium in pregnancy. No problems are anticipated with the administration of Calcium Lactate Tablets during lactation.' (SPC section 4.6). Section 4.2 gives a higher daily dose of 3-4 tablets (0.9-1.2 g) for pregnant women during the third trimester and during lactation.

Calcium lactate

Brand names: various

Calcium lactate is an oral calcium salt used as a dietary supplement to prevent or treat calcium deficiency.

Adult dose

Dose: Calcium deficiency states, as a therapeutic supplement (calcium lactate 300 mg tablets, each equivalent to 0.96 mmol calcium): adults including elderly - 1-2 tablets (300-600 mg) daily. Pregnant women (during the third trimester) and during lactation - 3-4 tablets (0.9-1.2 g) daily
Route: Oral
Frequency: Daily
UK SPC section 4.2: 'Calcium Lactate Tablets BP should not be taken for long periods without medical advice. Adults including elderly: 1-2 tablets (300-600mg) daily. Pregnant women: (During the third trimester and also during lactation) 3-4 tablets (0.9- 1.2g) daily. Children over 3 years: One tablet (300mg) daily. For oral administration.' Strength (section 2): 'Each tablet contains 300mg Calcium Lactate BP equivalent to 0.96mmol calcium (Ca2+).' The mg figures are mg of calcium lactate salt, not elemental calcium. Section 4.1: 'Indicated for the treatment of calcium deficiency states as a therapeutic supplement in pregnancy, lactation, osteoporosis, post-gastrectomy malabsorption, osteomalacia and rickets.' The SPC prints no maximum daily dose. Scope: this card covers only the pinned 300 mg calcium lactate tablet; other calcium lactate preparations and strengths are not covered by this SPC.

Paediatric dose

Dose: Children over 3 years - one tablet (300 mg calcium lactate) daily
Route: Oral
Frequency: Daily
This is the label's own paediatric figure (SPC section 4.2, 'Children over 3 years: One tablet (300mg) daily'), not a scaled adult dose; the SPC gives no figure for children of 3 years or under. Section 4.4: careful monitoring of blood levels and urinary calcium excretion is necessary, particularly when high-dose calcium therapy has been used, especially in children. Verify any under-18 dose against a children's formulary.

Dose adjustments

Renal

No dose adjustment is stated in the SPC. Severe renal failure is listed as an example of severe hypercalcaemia / hypercalciuria states in which the product is contraindicated (section 4.3). Section 4.4: calcium salts should be administered with caution to patients with impaired renal function.

Hepatic

Not addressed in the SPC.

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

Contraindications

  • Severe hypercalcaemia and hypercalciuria (e.g. hypervitaminosis D, hyperparathyroidism, severe renal failure, osteoporosis due to immobility and decalcifying tumours such as plasmocytoma and skeletal metastases) (section 4.3)
  • Patients receiving therapy with cardiac glycosides such as digoxin must not be given calcium supplements (section 4.3)

Side effects

  • Calcium salts may cause constipation (section 4.8)

Interactions

  • Cardiac glycosides (digitalis, digoxin): calcium enhances the effects of digitalis on the heart and may precipitate digitalis intoxication - calcium supplements must not be given to patients on cardiac glycosides (sections 4.3 and 4.5)
  • Tetracyclines: calcium salts reduce their absorption (section 4.5)
  • Other compound vitamin or mineral preparations, which often contain additional sources of calcium: use with care (section 4.5)

Monitoring

  • Blood calcium levels and urinary calcium excretion: careful monitoring is necessary, particularly when high-dose calcium therapy has been used, especially in children (section 4.4)
  • Suspend treatment if serum calcium exceeds 2.625-2.75 mmol/litre (105-110 mg/litre) or if urinary calcium excretion exceeds 5 mg/kg (section 4.4)
  • Serum potassium in infants with hypokalaemia: elevation of serum calcium may further reduce serum potassium (section 4.4)
  • Caution in patients with impaired renal function, cardiac disease or sarcoidosis (section 4.4)
  • Should not be taken for long periods without medical advice (section 4.2)

Clinical monograph

How it works

It dissociates in the gut to provide elemental calcium, which is absorbed (partly vitamin D dependent) to maintain serum calcium, bone mineralisation and neuromuscular function.

Prescribing in practice

  • Avoid in hypercalcaemia and hypercalciuria, and use caution in severe renal impairment and in patients with a history of calcium-containing stones.
  • Space administration away from oral tetracyclines, quinolones, levothyroxine, iron and bisphosphonates because calcium impairs their absorption.
  • Co-administration of high-dose vitamin D or thiazide diuretics increases the risk of hypercalcaemia.

Monitoring

Check serum calcium and renal function periodically with prolonged or high-dose supplementation.

Counselling the patient

  • Take with or after food to aid absorption and reduce stomach upset.
  • Keep a gap between this and antibiotics or thyroid medication.
  • Report constipation, nausea or unusual thirst and increased urination.

Evidence & guidelines

Oral calcium salts are a standard, well-established means of correcting dietary calcium insufficiency.

Reference: NICE NG121; ROS; 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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