Health officials in Alberta are worried about kids accidentally overdosing when cannabis edibles hit store shelves.

Federal rules allowing for the legal sale of cannabis edibles, extracts and topicals went into effect Thursday.

Health Canada expects products such as pot-infused candy, baking and beverages will hit store shelves by mid-December.

"We do have some concerns," said Calgary's medical officer of health, Dr. Brent Friesen.

Doctors are particularly worried about kids getting into their parents' supplies.

A Canadian surveillance program documented more than a dozen cases of Canadian kids with serious or life-threatening illness caused by cannabis in the months around legalization.

Six were young children who accidentally ate their parents' or grandparents' edibles.

Friesen says even with a Health Canada requirement that edibles must not be appealing to youth, there is still a risk.

"So while they might not be gummy bears, per se, they're still potentially in chocolates or other products that are appealing to children and youth," he said.

Parents need to be sure to keep edibles safe and locked away from children, he says.

Friesen also notes that hospital visits have gone up since cannabis was legalized last year, and with edibles, it could be about to get worse.

"I think there's much greater potential for us to see it with this phase of implementation," he said.

That's partly because it can take a couple of hours to feel the effects of edibles, so people tend to ingest too much, too quickly.