Calcium lactate

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.