For decades, commonly held public health messages argued that calcium is good for your bones -- and the more of it people consume, the better protected they will be from fractures and osteoporosis. But two new studies published last week contend that this message is wrong.

The studies found that calcium supplements offered only a meagre, one-per-cent increase in bone-mineral density in those over 50. They also found that calcium supplements had little to no effect on the overall risk of fractures.

The New Zealand researchers behind the studies found that dietary calcium intake is not associated with risk of fracture, and there is no clinical trial evidence that increasing calcium intake from dietary sources prevents fractures.

They also concluded that the evidence that suggests supplements prevent fractures is "weak and inconsistent."

Dr. Ian Reid, one of the lead authors of the studies, said he believes most people taking calcium supplements should stop.

"I think people should, for the most part, stop taking calcium supplements, because they're not effective in terms of improving bone health," he told CTV News.

What's worse, the researchers argue, is too much calcium increases the risk of kidney stones and possibly heart attacks. They're encouraging governments to lower the recommended daily limit from a high of 1,300 mg per day for adults, to 800 mg.

Reid said it may take a while for doctors and dieticians to adjust to the new evidence, adding he believes that the body of evidence is "very clear."

But some doctors worry that the new message is too extreme.

Dr. Sandra Kim, from Toronto's Women's College Hospital, said people vary in their calcium needs, and some do need supplements.

"We want people to not jump to conclusions and realize that these articles don't really change our main message," she said. "We know that it doesn't prevent fractures, but adequate calcium intake is vital for general bone health."

Some European countries have already taken note of the growing case against too much calcium, and have started lowering their daily recommended intakes.

With a report from CTV News' Medical Correspondent Avis Favaro and producer Elizabeth St. Philip