To what extent calcium intake really protect your bones?

Ask someone how to prevent bone fractures and are likely to respond, "Get more calcium." Medical experts have tended to agree. For example, the Institute of Medicine recommends a calcium intake of 1 000 to 1 200 milligrams (mg) per day for most adults.  

But in the last five years we have also learned that calcium - at least in the form of supplements - is not without risk. An intake of 1000 mg of supplements was associated with an increased risk of heart attack, stroke, kidney stones, and gastrointestinal symptoms.

Now an analysis of reams of research concludes that calcium intake at this level to reduce fractures in people over 50 years and a related analysis indicates that increasing calcium intake has only a modest effect on bone density people of this age. Both were published online this week in the medical journal BMJ.

These results may seem surprising, but they are not a surprise to Dr. David Slovik, associate professor of medicine at Harvard Medical School professor and author of our health Osteoporosis Special Report: A Guide to Prevention and Treatment. "I do not think we ever thought that calcium reduced fractures in itself, it is part of a bigger picture," he said. You can not really say "enough calcium and you'll be fine."

What the analysis revealed 
The analyzes were performed by a team of researchers led by Mark Bolland Zealanders, who first identified the cardiovascular risk associated with calcium supplements. For the first analysis, which evaluated more than 70 studies on the effects of calcium supplements and dietary calcium in preventing fractures. 

In his view, the two randomized clinical trials and observational studies and studies vary considerably in terms of number of participants, the consumption of calcium, vitamin D, and how fractures were reported. The researchers found that, in particular calcium or calcium dietary supplements have been associated with fracture reduction.

In the second analysis, the researchers examined 59 randomized controlled clinical trials evaluating calcium intake and bone density. Fifteen of these studies included dietary calcium and calcium supplements 44 looked. Especially, to obtain at least 800 mg of calcium daily diet or take at least 1000 mg of calcium increase in bone density of an additional day. But bone density increased by only 0.6% to 1.8% - a too low to affect the risk of fracture.

Importantly, these studies included very few men. (Many people think that osteoporosis only affects women, but men can also develop osteoporosis.)

The study that started it all? 
Bolland and colleagues noted that a study they think may be responsible for calcium recommendations today. This study was a randomized controlled trial in 3800 French elderly women (average age 84) in assisted living. The women initially had low calcium intake (500 mg daily), low levels of vitamin D, and low bone density.  

Those who received 1200 mg of calcium and 800 international units (IU) of vitamin D a day for three years had a risk 23% lower hip fracture, and risk 17% lower fractures in particular those taking placebos . Women who took calcium builds bones also, while the placebo continued to lose. These findings - published in 1992 and 1994 - are often cited by the experts in the development of calcium recommendations for the general population. But Bolland argued that in healthy people, assets that have calcium deficiency and vitamin D are not subject to the same protection by taking lots of calcium.

What to do?
"The key is that you should not take calcium with the idea that this will prevent bone fractures," says Dr. Slovik. However, he noted that sufficient vitamin D and calcium is essential for bone health. A deficiency of either may increase the risk of diseases such as rickets and osteomalacia.

It is impossible to determine the amount of calcium each of us must do individually. Try to get as much calcium as possible food. If your doctor told you to get between 1,000 and 1,200 mg of calcium daily, you can add safely a daily calcium supplement of 500 mg or 600 without increasing the risk of heart attack or kidney stones. And do not forget vitamin D. No one disputes the recommendation for vitamin D - 600-800 IU per day, or from foods or supplements.
By: Beverly Merz