Chalk and cheese: symptomatic hypocalcaemia during paediatric anti-tuberculous therapy.

Standard anti-tuberculosis therapy may disrupt normal vitamin D metabolism and consequently calcium homeostasis, but this is previously unreported in paediatric patients. We describe two children developed symptomatic hypocalcaemia secondary to hypovitaminosis D, which had been precipitated by rifampicin and isoniazid. The complex relationship between tuberculosis, anti-tuberculosis therapy, vitamin D metabolism and calcium, together with the clinical implications, are discussed.