Recent research published in the British Medical Journal shows that calcium supplements might be deadly. Why do we take calcium? When you're a kid you need calcium to make strong bones. When you're an adult you need it to keep your bones strong. For years, we doctors have been telling nearly every woman, and most men, to get 1,500 milligrams a day of calcium. That nearly always means a calcium supplement for good bone health. Well, guess what? We were wrong.
First, the data showing that the 1,500-milligram dose of calcium prevents broken bones isn't that strong. Two recent major studies show a modest 10 percent reduction in fracture rate. That's significant, but not mind-blowing.
Far more important for maintaining strong bones is weight-bearing exercise. And calcium, as many of you know, causes bloating and constipation. It also increases risk of a kidney stone by 20 percent.
Next, how do you get your calcium? The natural way is through food. Dairy is the best source, but calcium also comes from green, leafy vegetables such as spinach, kale and collards, as well as soybeans and sardines. When you eat calcium-rich foods, the calcium is absorbed in a slow, steady fashion. In sticking to the 1,500-milligrams-per-day mantra, we turned to calcium supplements. All calcium supplements, either the cheaper store brands or the overpriced "natural" brands, contain the inorganic mineral calcium. There is no such thing as "organic" calcium. Swallowing a calcium supplement is not the same as digesting calcium from food.
For the study cited in the British Medical Journal, investigators followed 24,000 people, looking at what calcium-rich foods they ate and who took calcium pills. After gathering data for 10 years, they concluded that those who took calcium supplements of any kind were 90 percent more likely to have a heart attack. That's shocking to me, because I was on the calcium bandwagon just like so many other doctors.
Here's what we think is happening in your body: One hour after you swallow your calcium pill, you have a super-high level of calcium in your bloodstream. Researchers now believe it's that calcium bump, that sudden high level caused by taking a calcium supplement, that's causing heart attacks.
This isn't the first study to show this. A recent study out of Australia of frail elderly women showed that those who took calcium supplements were 76 percent more likely to die of a heart attack. The study also showed that the minimal amount of calcium for optimal health is about 800 milligrams a day, that's about two containers of yogurt.
My spin: Shoot for 800 milligrams of calcium a day from food, and toss those supplements. That's what I'm going to do. This provocative research is controversial, and many doctors won't agree with me.
So you make the call - and that just might mean a visit to your doctor to discuss things. This study combined with others shows that calcium supplements are not pristine, they are risky.
If you're concerned about osteoporosis or if you have it, then go the other natural route: Put down this newspaper and go for a walk - your weight-bearing exercise - and eat your yogurt. It's a lot more fun than swallowing a chalky pill.
Dr. Zorba Paster is a family physician, university professor, author and broadcast journalist. He also hosts a popular call-in program on WNED radio each Saturday at 3 p.m.