Strontium - Treatment for Osteoporosis

If you are concerned about the bone-thinning disease osteoporosis, one treatment you may have heard of and considered is strontium. WebMD takes a look at the potential benefits and risks of this supplement purported to improve bone health.

What Is Strontium?

Strontium is a trace element found in seawater and soil. The main dietary source of strontium is seafood. Foods with lesser amounts include whole milk, wheat bran, meat, poultry, and root vegetables.

Strontium is chemically similar to calcium. It appears to play a role in the formation of new bone while slowing the breakdown of old bone, and thus may influence bone density. There is some evidence that women with osteoporosis may not absorb strontium as they should.

In several European countries and Australia, a patented form of strontium, called strontium ranelate (Protelos), is available as a prescription medication for the treatment and prevention of osteoporosis and related fractures. Protelos is not approved in the U.S.; however, nonpatentable forms of the element, such as strontium citrate, are widely available as nutritional supplements in supermarkets and health food stores.

Possible Benefits of Strontium

A 2004 study from the New England Journal of Medicine suggests strontium ranelate may be protective for women with osteoporosis. In the three-year study of postmenopausal women with osteoporosis, strontium ranelate increased bone density in the hip and spine and reduced the risk of fracturing a vertebra by 41% compared to placebo. A longer-term study published by the same group in 2009 showed strontium ranelate, compared to placebo, reduced the risk of vertebral fractures by 33% over four years.

Unfortunately, the supplement forms of strontium have not been tested in large studies like the prescription drug strontium ranelate. Furthermore, supplements are not regulated the same way as prescription drugs, so it's not always possible to know the quality of the supplement you are taking or the amount of the active ingredient in a product.

Possible Risks of Strontium

When taken in recommended doses, strontium supplements appear to be safe. Aside from occasional mild gastrointestinal upset, including diarrhea, side effects are rare.  However, excessive doses of strontium may replace too much calcium in the bone and hurt vitamin D metabolism, causing them to weaken.

Use with caution if you have kidney problems or history of blood clots.

What Else You Should Know About Strontium

The optimal strontium intake is not known. If you are on medication treatment for osteoporosis, it is not known whether strontium supplements will enhance or diminish the benefits.

Also, it's important to note that while strontium may increase bone density, improvements seen on bone density testing may appear more impressive than they really are. That's because strontium in bone can affect interpretation of bone mineral testing. If you are taking strontium regularly, you should let the radiologist know before you have the bone mineral density test.