CALGARY -- A jury is expected to begin deliberating today about whether a Calgary couple is responsible for their 14-month-old son's death.

Jennifer and Jeromie Clark have pleaded not guilty to criminal negligence causing death and failure to provide the necessaries of life for their son John.

Queen's Bench Justice Paul Jeffrey is to instruct jurors this morning on how to reach a verdict, after which they are to be sequestered.

The trial heard the Clarks brought their son to hospital on the afternoon of Nov. 28, 2013, and that he died the next day following a seizure and two cardiac arrests.

The Crown says John was on the verge of death when he arrived in hospital and that his parents played with his life by not seeking treatment sooner.

The Clarks' lawyers say doctors at the Alberta Children's Hospital are to blame because they raised the boy's sodium and fluid levels too aggressively.

Jurors were shown pictures of John after he died. He had blackened toes and a red rash in a swirling pattern that covered 70 per cent of his body. It was initially believed the rash was eczema, but Crown witnesses said was likely to have been due to a nutritional deficiency.

Emergency and intensive care doctors testified the boy had an abnormally low heart rate and temperature, a sign he could be in the final stages of an overwhelming infection.

The forensic pathologist's report said John was malnourished and died from sepsis.

Defence lawyers said John was sick when he arrived in hospital, but was not near death. Nor was he malnourished or septic, they argued.

A defence witness, former Alberta chief medical examiner Anny Sauvageau, suggested John's underlying illness was due to hormonal issues. She testified that doctors infusing him with saline caused his death.