Heartbroken Aussie family's warning about protein supplements after young mother's death.

Earlier this year Meegan Hefford had been ramping up her diet and exercise regime ahead of a bodybuilding competition. But what the mum-of-two couldn’t have known is that the protein supplements she was taking to build muscle were actually harming her.

On June 19 the 25-year-old was found unconscious in her home in Mandurah, an hour’s drive south of Perth and rushed to hospital. Days later she was pronounced dead.

Now, her heartbroken family is sharing her story as a warning to others of the potential dangers of over-consumption of protein supplements.

Meegan's mum Michelle White told Seven News that her daughter had a rare, undiagnosed condition that meant her body couldn't break down protein properly, causing a buildup of ammonia in her blood and fluid in her brain.

The condition, urea cycle disorder, affects around one in 8000 people, many of whom, like Meegan, don't know they have it. Meegan's only clue was that she was feeling lethargic in the weeks before her death.

"There was just no way of knowing she had it because they don't routinely test for it,” Ms White told Seven News.

Ms White said she didn't know her daughter was supplementing her already high-protein diet with protein shakes until she found containers in her kitchen after her death.

"There's medical advice on the back of all the supplements to seek out a doctor but how many young people actually do?"

Meegan, who was studying to be a paramedic at the time of her death, leaves behind a seven-year-old daughter and five-year-old son.

"Losing Meegan, it's so awful and I still can't believe she's gone but I have to focus on the positives that at least I had 25 years with her and she jammed so much into her life, it's almost like she knew her time would be short," she told Perth Now.

Ms White said she hopes that her daughter's death serves as a warning to others to reconsider the need for supplements.

That is backed up by medical bodies around the world - who says a diet rich in protein from whole foods is the best way to go and that protein supplements can offer only little benefit to most healthy people.

Similarly, Nutrition Australia's website states increased protein intakes "can generally be achieved by the overall increased food intake required to fuel training. Protein supplements and shakes can be very expensive and are not usually necessary."