Hypocalcaemia not associated with hypoalbuminaemia or 25(OH)-Vitamin D deficiency is rare and should be referred to a specialist clinic. 25(OH)-Vitamin D deficiency can often be treated safely by GPs, unless it is associated with renal impairment and secondary hyperparathyroidism, in which case a nephrology referral is required. An endocrine referral is required if deficiency is associated with pregnancy, co-existent primary hyperparathyroidism or the patient is receiving warfarin. The key role of the GP in managing hypercalcaemia is to distinguish between malignant and parathyroid causes in order to make the appropriate specialist referral (oncology, endocrine or renal). Severe hypercalcaemia (greater than 3.5 mmol/L or hypercalcaemia with dehydration, abdominal pain or reduced consciousness is a medical emergency.