A 20 year old female presents with a history of perioral tingling and tingling
of her arms and feet and muscle cramps. No other symptoms.
No previous illnesses of note.
Corrected calcium 1.74 mmol/L
Urea 80 mmol/L
Creatinine 90 mmol/L
In this patient which one of the following investigations would you arrange
Parathyroid hormone concentration
Vitamin D assay
Urinary calcium concentration