Reality check: How much calcium is too much?

Justin Sullivan/Getty Images

TORONTO – Could you be dining on too much milk and cheese than your body can healthily take on?

Swedish researchers’ findings on calcium caused some concern: after studying more than 60,000 women over the course of nearly 20 years, they suggested that high intake of calcium is linked to an increased risk of death.

Parents raise their children on milk for their bones and teeth but stories such as “Can too much calcium in your diet be deadly?” and “The dangers of too much calcium” warned readers to watch their intake of the nutrient – especially if they’re worried about a heart attack or stroke.

Global News looks at the study findings, counter-arguments and the verdict from a Canadian expert.

Story continues below advertisement

The study’s findings:

Uppsala University researchers followed the health of 61,443 Swedish women born between 1914 and 1948 for a 19-year span. Data on their health was retrieved from the Swedish Cause of Death Registry. A record of their eating habits was logged in other decades-long studies.

During the study, about 17 per cent of the women died. And about 3,900 of the 12,000 died from cardiovascular disease while another 2,000 died from heart disease, the study reports.

The research suggests that the highest rates of these deaths occurred in women who had an average daily dietary calcium intake of more than 1,400 milligrams. On the other hand, higher-than-average death rates were also documented in women whose daily intake of calcium was below 600 milligrams.

The latest health and medical news emailed to you every Sunday.

The study was controlled for physical activity, education, smoking, alcohol and other dietary factors, the New York Times notes in its coverage of the study.

Sound bite: “Emphasis should be placed on people with a low intake of calcium rather than increasing the intake of those already consuming satisfactory amounts,” the authors said in a statement.

The counter-argument:

In response to the studies, Dr. John Cleland told health website, that the study results are “extremely complex … with rather weak findings.”

Story continues below advertisement

Cleland is from the Hull York Medical School in the United Kingdom.

He notes that the study’s participants who had high calcium intake were confined to those taking supplements, and not women eating their daily calcium values.

Sound bite: “It’s not the diet but the pills that are the problem.”

Canadian expert weighs in:

Carol Dombrow, who’s been a registered dietician with the Heart and Stroke Foundation for almost 25 years, says that Canadians should consider how much calcium they’re taking in in a day.

In the study, women at risk of heart disease were consuming more than 1,400 mgs of calcium a day. That’s not what guidelines recommend, Dombrow notes.
“They’re going overboard,” she told Global News.

“What this study does is stress to people that more is not necessarily better. It means you should discuss this with your family physician and consider your individual risk factors.”

Still, Dombrow says the findings “make sense.” Too much calcium in your bloodstream can lead to vascular calcification – a hardening in the body – to an increased risk of blood coagulation and stiffness in your arteries.

“Those things may be contributing to these cardiovascular outcomes. So it’s not far-fetched,” she said.

Story continues below advertisement

Calcium is the mineral that makes up your bones and teeth and keeps them strong. It’s also in your blood and soft tissue.

Osteoporosis Canada suggests that Canadians between 19 and 50 years old should be consuming about 1,000 milligrams of sodium a day at most. Meanwhile, those 50 and older should have about 1,200.

That includes what you’re getting from supplements.

A glass of milk makes up about a third of your day’s intake at 300 mg. A few cubes of cheese also make up another serving, about 245 mg.

If you’ve had your day’s meals and you top it up with a calcium supplement, chances are you’re exceeding the day’s amounts.

“There is such thing as too much calcium. And I think for any nutrient, it is hard to get excess from food, but it’s not so hard to get excess from supplements, so there’s where you have to be more cautious.”

If you’re unsure of where you stand on calcium, talk to your family doctor, Dombrow suggests.


Sponsored content