Alongside strengthening bone, calcium is used in the clotting cascade, in muscle contraction, and in nerve-signalling. As such, low levels can lead to coagulopathy, smooth and skeletal muscle-spasms, heart problems, altered sensation and even seizures. Acute hypocalcaemia that is severe (<1.9 mmol/L) or symptomatic can be life-threatening and necessitates urgent treatment. It is often initially