MS-2494

A 35-year-old male vegan athlete visits the clinic complaining of muscle spasms and tingling on his lips and tongue. During a blood pressure measurement, his hand involuntarily spasms.

The following are the results of his blood tests:

Calcium 1.7 mmol/L (2.1-2.6)
Parathyroid hormone 90 pg/mL (16 – 65)
Vitamin D 12 nmol/L (30 – 50)

What is the probable cause of this patient’s electrolyte imbalance?