Strontium Ranelate and Strontium Citrate Studies

Numerous studies on sr. ranelate found increasing BMD correlated with decreasing fracture risk (references #16 and #21-25 listed at the end of the Comb Study cited below). The French pharmaceutical company, Servier, funded the research on sr. ranelate to market the drug in Europe and elsewhere. Taking a drug through all the required clinical trials takes millions of dollars and the resources of a large company like Servier, which is present in 140 countries, with more than 20,000 employees, including close to 3000 in Research and Development (R&D).

Strontium citrate is not patentable and is sold as a supplement in the U.S. and Canada. There is no monetary incentive for a large pharmaceutical company to do research on strontium citrate. Any research on sr. citrate is most likely to come from universities that have obtained grants. We will continue to see small-scale strontium citrate studies that will add to our knowledge. I do not expect to see large-scale clinical trials involving thousands of subjects taking strontium citrate over a period of several years. Those are the types of trials needed to prove fracture-risk efficacy.  

The following is a review of some significant studies on strontium citrate:

In 2007, two American researchers with SDM College of Dental Sciences in Buffalo, NY, presented their work on osteoblasts at a dental conference. They wrote: “The data support the hypothesis that strontium citrate increases the proliferative/alkaline phosphatase activity of human osteoblastic cells from alveolar bone. The results validate previous research that has been done with other forms of strontium in clinical studies and rodent calvarial cells and indicates that strontium citrate could be a promising agent in treating oral as well as systemic bone disorders.”  The abstract of their paper is available here: http://iadr.confex.com/iadr/2007orleans/techprogram/abstract_89231.htm

 In 2012, two Canadian researchers, one with the University of Alberta, the other with the University of Calgary, published the results of a one-year study called the Combination of Micronutrients for Bone (COMB) Study. The daily protocol consisted of: docosahexanoic acid or DHA (from Purified Fish Oil) 250 mg, vitamin D3 2000 IU, vitamin K2 (non-synthetic MK7 form) 100 ug, Strontium citrate 680 mg elemental strontium, and elemental magnesium 25 mg/day. Dietary sources of calcium were recommended. Daily impact exercising was encouraged. The researchers concluded: “This combined micronutrient supplementation regimen appears to be at least as effective as bisphosphonates or strontium ranelate in raising BMD levels in hip, spine, and femoral neck sites. No fractures occurred in the group taking the micronutrient protocol. This micronutrient regimen also appears to show efficacy in individuals for whom bisphosphonate therapy was previously unsuccessful in maintaining or raising BMD. Prospective clinical trials are required to confirm efficacy.” The complete article is available here: http://www.hindawi.com/journals/jeph/2012/354151/

In July, 2012, four researchers at Ryerson University in Toronto, Canada, published a study in “Bone” entitled: “Monitoring bone strontium levels of an osteoporotic subject due to self-administration of strontium citrate with a novel diagnostic tool, in vivo XRF: a case study.” This study is significant because it used a non-invasive method (not an invasive method, such as bone biopsy) to analyze the strontium levels of bones in an osteoporotic patient who began taking strontium citrate for the study. Therefore, it was possible to obtain her baseline bone strontium levels prior to initiation of therapy with strontium citrate. The researchers wrote: “By 120 hours, the increase (in bone strontium level) was statistically significant at 0.68 ± 0.07 and 0.93 ± 0.05 (for the finger and ankle), respectively. Further increases occurred within an interval of 90-180 days, with the most recent, after 800 days, at the finger and ankle being 7 and 15 times higher than the initial baseline reading. The intriguing results show bone strontium incorporation and retention follow a pattern, suggesting strontium levels, at least in the ankle, do not plateau within two to three years and will continue to increase over time, as an individual takes strontium supplements. The ability of this IVXRF (in vivo X-ray fluorescence) system to monitor and measure bone strontium levels over time provides a useful diagnostic tool to help gain insight into strontium bone kinetics.” The abstract can be read here:  http://www.ncbi.nlm.nih.gov/pubmed/22549020