Safety of Strontium

Published on March 06, 2017 by Dr. Paul Hrkal

There have been some recent concerns about strontium’s safety as well as a lack of information regarding strontium citrate. Let's set the record straight on strontium. 

What is Strontium & Who Does it Help? 

Strontium is a natural element found in nature, it's largest quantities are found in the ocean and consequently in certain bony fish. In the human body, 99% of the strontium is found in the bone. Because strontium and calcium have very similar molecular structures, the body treats them much the same. We are now starting to understand the mechanics of how strontium actually works. It is thought that strontium activates calcium-sensing receptors and also influences the expression of genes that control bone formation and bone breakdown.

Bisphosphonates are a group of osteoporosis drugs known to work well for the short term but have devastating opposite effects after several years of use. In this case, bone fragility increasing as a result of the treatment is proven to be true in numerous clinical studies. Several studies have suggested that strontium ranelate is a possible solution for those who have experienced excessive bone deterioration after taking bisphosphonates. Strontium may therefore help restore bone health for victims of failed bisphosphonate treatment, albeit a slower recovery.

Some of the newest research has shown that strontium benefits men with osteoporosis the same as it does women. Strontium has also been shown to be a potential treatment for knee osteoarthritis, providing some structural support, reducing pain symptoms and improving physical function of the knee joint in osteoarthritis patients. The use of strontium in bone and heart implants may even be on the horizon since new research shows that it is degraded slower than other materials like magnesium typically used in implants. 

Which Form of Strontium?

Strontium has been combined with various compounds to form strontium salts such as strontium salicylate, strontium cinnamate, strontium chloride, strontium lactate and strontium gluconate, all of which have been used for medical purposes. Ranelic acid is a synthetic compound not found in nature and is the most recently studied partner for strontium. However, it is the elemental strontium that is important. Early studies demonstrated this fact by basing their doses, evaluations and conclusions on the amount of elemental strontium given and not those of the entire compound. In these early studies, up to 1750 mg/day of the strontium ion from strontium gluconate and strontium lactate were found to be safely tolerated in patients with bone cancer or postmenopausal osteoporosis receiving strontium from three months to three years.

What About the Adverse Effects of Strontium?

Strontium ranelate has been associated with, but necessarily the cause of, rare cases of gastrointestinal disturbances, minor skin rashes, blood clots and memory loss, in descending order. Two other studies, that obtained information from physicians, found that people who had osteoporosis appeared to have a higher risk of blood clots regardless of whether or not they had been treated with strontium ranelate, bisphosphonates or other post-menopausal osteoporosis treatment. For strontium ranelate, the blood clot effects were measured within the first year of use. 

Several human studies on strontium citrate have emerged, producing the same positive results as other forms of strontium in combination with other important bone health nutrients and a healthy lifestyle. In the two recent studies using strontium citrate for one year, there were no adverse effects of any kind either self-reported or from blood samples (inconsistently or sporadically taking strontium may not produce positive results). Further, strontium citrate has not produced the same adverse effects as strontium ranelate during the first year of use.

Can Strontium Supplementation Make Your Bones More Fragile?

There has been some concern in the past few years that strontium may eventually increase the risk of fractures by reducing tensile strength of the bone (the ability of bone to resist pulling forces). All of this concern has been caused by a single article that claimed that strontium accumulates more so in the thicker outer portion of the bone (cortical bone) rather than the inner matrix, or cancellous bone, that is most affected by osteoporosis. In theory, this would increase the risk for breakage. However, a brief overview of several studies will show us that this theory has been debunked. In fact, the opposite has been shown to be true, with several long-term human studies showing good safety and effectiveness.

Since its discovery until today, strontium’s popularity has risen and fallen on waves of uncertainty of whether it is safe, whether it is effective, what it is effective for, how it works, and how long it works for, and other answered questions. Strontium has indeed been safely and effectively used with relatively few adverse effects for periods of up to 10 years! In spite of unfounded arguments, the evidence points to the overwhelming safety and effectiveness of strontium for healthy bones.