The sister of a woman whose partner claimed she died because she drank too much Coca-Cola says she does not hold the company responsible.

However, the woman's partner and mother-in-law say warning labels should be put on the drink.

An inquest for mother-of-eight Natasha Harris was held in Invercargill yesterday. Ms Harris died on February 25, 2010.

Otago-Southland coroner David Crerar did not make any preliminary findings after yesterday's inquest, however pathologist Dan Mornin said he believed Ms Harris died of cardiac arrhythmia and it was likely she was suffering from hypokalemia (low potassium) along with caffeine toxicity, which could have contributed to her death.

When asked by Mr Crerar whether it was probable her consumption of Coca-Cola had caused the hypokalemia and arrhythmia, Dr Mornin said yes, along with poor nutrition and caffeine.

At the inquest, Ms Harris' partner, Chris Hodgkinson, said his partner consumed between 4.5 and 8 litres of Coke a day for several years before her death, and he believed this had contributed to her death.

His mother, Vivien Hodgkinson said after the inquest that warning labels should be put on Coke products.

However, Ms Harris' sister Raelene Finlayson yesterday said no-one had forced her sister to drink the Coke, and she did not hold Coca-Cola responsible for her death. "Nobody forced Tasha to drink all that ... it's like anything, we all know anything in moderation is okay," she said.

The last time she saw her sister, about a week before her death, she had looked unwell, Ms Finlayson said. She told her she should see a doctor, but her sister put her children before herself.

"They didn't live the best lives, but Tasha always put those kids first. They never went without food or anything like that."

In a statement issued after the inquest, Coca-Cola Oceania public affairs and communication manager Karen Thompson, who also attended the inquest yesterday, said the safety of the company's products was paramount.

"We concur with the information shared by the coroner's office that the grossly excessive ingestion of any food product, including water, over a short period of time with the inadequate consumption of essential nutrients, and the failure to seek appropriate medical intervention when needed, can be dramatically symptomatic ...

"We believe that all foods and beverages can have a place in a balanced and sensible diet combined with an active lifestyle.," the statement says.

The company's thoughts were with the Hodgkinson family, but as the coroner had not yet issued findings into Ms Harris' death, it was not appropriate for Coca-Cola to comment further, it says.

At the inquest, Mr Hodgkinson said he found his partner slumped against a wall after she called out to him. Ambulance staff were unable to revive her, he said.

TOO MUCH OF ANY LIQUID CAN BE DEADLY

Drinking up to eight litres of any liquid a day can kill you, regardless of how much sugar or caffeine it contains, a Wellington dietician says.

Foodsavvy's Sarah Elliott said that when "extreme" amounts of fluid were consumed regularly, the body's cells could rupture.

"Ten litres of fluid a day could kill you, no matter what it is."

Specialists recommend that humans do not drink more than four litres of liquid a day. Natasha Harris's daily intake of Coca-Cola would have given her up to a "shocking" 3424 calories and 864 grams (or 3 1/2 cups) of sugar, Mrs Elliott said.

Also, the combination of caffeine and sugar encouraged addiction, and soft drinks were shown to make bones thinner and cause osteoporosis.

Mrs Elliott had one client whose five-litre-a-day Coke addiction had led to sweating and problems with his weight, skin and teeth.

There were problems when someone with an addictive personality was faced with choosing between cheap soft drinks and more-expensive healthy ones, Mrs Elliott said.

"Addictions are serious and she [Ms Harris] would have needed therapy to get through that, and would not have been able to just stop."

- © Fairfax NZ News