The Latest Research on Strontium

Updated: March 31, 2023

Lara Pizzorno is the author of “Your Bones: How You Can Prevent Osteoporosis and Have Strong Bones for Life – Naturally” and a member of the American Medical Writers Association with 29 years of experience specializing in bone health.

Recently we asked Lara if she would help us provide a series of short, ongoing videos to help you (our customers and readers) stay up to date on the latest facts and science related to bone health.

In this latest video, Lara discusses the latest strontium research – both for strontium ranelate and strontium citrate. Watch the video below (or read the transcript provided) and let us know what you think in the comments. 🙂

https://www.youtube.com/watch?v=gtVCDmtZ5dY

Hello, my name is Lara Pizzorno the author of “Your Bones” and I am here today to share some information with you about the latest research on strontium. Both the natural form of strontium which is strontium citrate, that’s available as a supplement and also the unnatural form of strontium, strontium ranelate, which is still being prescribed in the European Union although with lots of restrictions now.

So if you’ve read “Your Bones” or if you’ve seen my blog post on strontium on AlgaeCal’s website then you already know that I recommend and personally benefitted from using the natural form of strontium, strontium citrate, which AlgaeCal provides in its Strontium Boost supplement. But I do not recommend and would never personally use: the drug form of strontium which is called strontium ranelate and it continues to be prescribed although now with further restrictions because it is so potentially harmful. In Europe where it’s sold under its trade names Protelos and Osseor.

So in this video, I would like to update you about the latest research on both forms of strontium. The natural form, strontium citrate and the unnatural form, strontium ranelate. And I’d like to start with the drug form first.

On January 13th on 2014, The European Medicines Agency Pharmacovigilance Risk Assessment Committee, recommended strontium ranelate which I mentioned is sold under the names of Protelos and Osseor should not longer be approved by them to treat osteoporosis because this is a drug that people can get insurance cover for in the European Union still, unfortunately. Back in April of 2013 the European Medicines Agency had first recommended severely restricting the use of Protelos and Osseor because both have been strongly associated with increased risk of heart problems. But in 2014 they questioned even how well the severe restrictions they put in place in April of 2013 were going to work to reduce cardiovascular risk in patients prescribed these drugs and how well they can actually be working in clinical practice in other words real life. So the Pharmacovigilance Risk Assessment Committee went on to conduct an in depth review on the benefits of strontium ranelate and what they found out was, they didn’t really have very many. They found that out of every 1000 patient years there were 4 more cases of heart problems, including heart attacks and 4 more cases of blood clots or blockages of blood vessels with strontium ranelate than with placebo and they also found that strontium ranelate was clearly associated with a number of other risks including very serious skin reactions that demanded hospitalization, disturbances in consciousness, seizures, hepatitis, which is liver inflammation and a reduction of blood cells being produced in bone marrow. Our blood cells get produced in blood marrow so this adverse effect is particularly disquieting.

With regards to its benefits the Pharmacovigilance Risk Assessment Committee found that strontium ranelate has only been shown to have very modest benefits in osteoporosis.

In every 1000 patient years, which is the equivalent of 1000 patients being treated for a year, strontium ranelate may and I emphasis may, not for sure, prevent possibly 5 non spinal fractures, 15 nonvertebral fractures and less than half of one hip fracture, so 60% of your bone can break but the other 40% strontium ranelate will cover you – not too terrific.

Pharmacovigilance Risk Assessment Committee weighed these meager benefits against strontium ranelate’s known risks and concluded the balance was not favorable. So they recommended that strontium ranelate be suspended and this recommendation was sent to the Agency’s Committee for Medicinal Products of Human Use, which reviewed everything again and issued a final opinion at its meeting on January 20-23 in 2014. So if you know about the money, power and political influence that is wielded by Big Pharma, you probably will not be surprised to hear that despite everything: poor results, lots of adverse effects and high costs, this is not an inexpensive drug, Protelos/ Osseor (strontium ranelate) continues to be authorized in the European Union to treat severe osteoporosis. But it has very severe restrictions. It cannot be prescribed to patients that cannot be treated by any other medicine approved for osteoporosis, patients who have heart or circulatory problems may not use the medicine, before starting treatment doctors much assess patients risk of heart disease and high blood pressure and must continue to check their intervals while the patient is using this drug. Strontium ranelate cannot be prescribed to anyone who has had any kind of heart or circulatory problems and its treatment must be stopped if the person develops ischemic heart disease, peripheral arterial disease or cerebrovascular disease or uncontrolled high blood pressure. Big surprise. Well the final European Medicine Agency’s recommendation was based on an analysis of pooled data from randomized study in 7500 postmenopausal women with osteoporosis. The results of this huge study showed a 60% increase in risk of heart attack from strontium ranelate compared to placebo with a relative risk increase ranging from 1.07-2.38. In other words a 7% to 238% increase in risk and a 50% increased risk of deep blood clot formation, in other words venous thrombotic and embolic events. The increased of risk here ranged from 1.04- 2.19 so a little bit over 100% to over 220% increase in risk.

In Croatia, HOMED, which is their agency for medicinal products and medical devices had already removed strontium ranelate for sale after they received 24 very significant adverse reaction reports. 7 of which were related to skin, 7 were neurological and 1 was a blood adverse reaction. Out of these 24 reports, 9 of them were considered very very serious and among these, 3 were related to heart adverse reactions, atrial fibrillation, premature heart contraction and arrhythmias and 2 to severe skin reactions, so severe that they caused hospitalization and people can suffocate when their face swells really quickly. So strontium ranelate is no longer approved for sale in Croatia but you can still get it in the European Union.

Now for the really good news, these severe reactions and all the restrictions on strontium ranelate use have finally driven researchers to take a look at strontium citrate, the natural form of strontium, which has never been shown to cause the adverse reactions caused by strontium ranelate and its beneficial effects were the reason that strontium ranelate was created. It was created in the laboratory for one reason only, so that a natural substance could be patented, more money could be made on it.

So the first new paper that came out on strontium citrate, the natural form, reported on bone levels of strontium on a woman volunteer, who had been recruited in December of 2008 as part of the Ryerson-McMaster University Strontium and Bone Research Study. This is a large ongoing study that’s been continuing for a number of years now. And this woman’s bone strontium levels were measured twice weekly, weekly and then monthly intervals. She was given strontium citrate supplements at 680 mg per day which is the same thing that you get with Strontium Boost. And an increase in her strontium levels in her bone began to be seen after just 24 hours. Increases continued to be seen at each measurement interval with the most recent, which was taken after 800 days, which showed incorporation of strontium at the finger and ankle, they measured there because it’s easy to see the measurement of cortical and trabecular bone and they were 7 and 15x higher than the baseline reading.

What’s important about these results is that they show that strontium incorporation into bone and its retention into bone does not plateau in 2-3 years but continues to increase over time.

The next study to be published in bone, came out in January 2013 and it was an animal study a rat study and the objective was to quantify bone strontium accumulation in female spread dawley rats who were administered strontium citrate and compare these levels to rats that were given strontium ranelate the drug or placebo over the period of 8 weeks. Bone strontium levels in rats that were administered strontium citrate were found to be significantly greater than the bone strontium levels of rats that were given strontium ranelate or placebo. This was partly due to the finding that strontium citrate provided a greater amount of elemental strontium than did strontium ranelate. When this was factored into the analysis, differences in bone strontium levels between the rats receiving strontium citrate versus those getting the natural drug strontium ranelate form weren’t quite as wide, but both forms of strontium resulted in very significant increases of bone strontium levels and strontium citrate did a better job delivering strontium to bone than strontium ranelate.

The next paper to be published just came out this past January so January 2014, this was a human study and it involved 10, 9 of whom had osteopenia or osteoporosis. These 10 volunteers were again recruited by the large ongoing Ryerson and McMaster University Strontium and Bone Research Study and they agreed to have their bone strontium levels measured as they self supplemented with strontium supplements of their choice. Not surprisingly, they all chose to use strontium citrate supplements. Levels of strontium in their fingers and ankles to represent cortical and trabecular bone were measured using X-ray fluorescence and the baseline readings represented their natural bone strontium levels before strontium supplementation, since all volunteers had no prior intake of strontium supplements or medications. Once strontium supplements were started, a 24 hour reading was taken followed by frequent measurement ranging from weekly to biweekly to monthly. The longest volunteer participant was 1535 days or 4 years. So after just the first 24 hours, average strontium signals began to rise in these women and bone strontium levels continued to increase throughout the study, indicating that bone strontium levels will continue to rise in bone even after 4 year of strontium supplement intake. Interestingly, the strontium signal varied widely between these individual women, so much so that after 3 years the highest strontium signal observed averaged 28 for the finger and 26 for the ankle in one volunteer, compared to just 3 and 4.5 for the finger and ankle in another volunteer.

So what does this mean?

Well, as I keep saying, each of us is unique! Not everyone is going to benefit from every single thing and in exactly the same way, but some will benefit greatly from strontium citrate and some will benefit a little less but the key point here is that everyone benefited (you can read about the science-backed benefits of strontium here). Importantly, unlike strontium ranelate, not a single adverse effect was reported in any of the participants in this 4 year study using strontium citrate. So I hope this encourages you that if you’re not using strontium citrate as part of your bone building program, to consider it and discuss it with your doctor and I hope the information has helped and I hope you’ll tune in next time. Thanks, bye!

If you want to learn more about strontium after watching Lara’s video, head to our dedicated strontium page.


Sources:

European Medicines Agency’s Pharmacovigilance Risk Assessment Committee findings regarding strontium ranelate:

http://www.halmed.hr/?ln=en&w=novosti&d=2014&id=998&p=37

http://www.ema.europa.eu/ema/index.jsp?curl=pages/news_and_events/news/2014/01/news_detail_002005.jsp&mid=WC0b01ac058004d5c1

Moise H, Adachi JD, Chettle DR, et al. 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. Bone. 2012 Jul;51(1):93-7. doi: 10.1016/j.bone.2012.04.008. Epub 2012 Apr 23. PMID: 22549020

Wohl GR, Chettle DR, Pejović-Milić A, et al. Accumulation of bone strontium measured by in vivo XRF in rats supplemented with strontium citrate and strontium ranelate. Bone. 2013 Jan;52(1):63-9. doi: 10.1016/j.bone.2012.09.002. Epub 2012 Sep 17. PMID: 22995463

Moise H, Chettle DR, Pejović-Milić A. Monitoring bone strontium intake in osteoporotic females self-supplementing with strontium citrate with a novel in-vivo X-ray fluorescence based diagnostic tool. Bone. 2014 Apr;61:48-54. doi: 10.1016/j.bone.2014.01.002. Epub 2014 Jan 14. PMID: 24434614

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  1. Doncella Inglis

    June 16, 2016 , 10:14 pm

    Is strontium incorporated into bones more readily than calcium? If so could it be harmful to have such high strontium levels as these articles suggest happens with the participants in the clinical trials over the years? Is there a maximum level of safe strontium in bones?

  2. Lara Pizzorno

    June 18, 2016 , 6:16 am

    Hi Doncella,

    Great questions –

    I’ve reviewed the latest papers. Per usual, the majority of the papers discuss research conducted on the drug, strontium ranelate, which, as I’ve written about at length, has numerous adverse cardiovascular and immunological effects – unlike natural forms of supplemental strontium, which have never been shown to cause any adverse side effects.
    However, the strontium ranelate papers are useful for our purpose here since it’s agreed in the research that there’s no evidence to suggest that strontium ranelate is differently absorbed into bone or retained in bone compared to any other strontium salt, i.e., compared to strontium citrate. In the strontium ranelate research on osteoporotic women, in which study length averages between 3–5 years, the resulting replacement of calcium by strontium is a substitution of up to one atom in every one hundred of calcium being replaced by a strontium atom – definitely not enough to have an adverse effect on calcium levels in bone!


    Is strontium incorporated into bones more readily than calcium?

    No. Strontium is not more readily absorbed or incorporated into bone than calcium. Both minerals use the same transport / absorption mechanisms, and furthermore, calcium will always be preferentially absorbed over strontium. This is why strontium should always be taken at a time separated by 3-4 hours from when calcium is consumed.

    In addition, strontium is best absorbed at night, which is when bone resorption/remodeling is most active. In the recently conducted Ryerson and McMaster University Strontium in Bone Research Study, the participants absorbing strontium most effectively took their strontium citrate supplement at night at a dose of 341 mg/d, while the study participant who absorbed the least strontium took a dose of 680 mg/d, but took her supplemental strontium during the day. This suggests that a dose of 341 mg/d (half the 680 mg/d dose used in the studies assessing the effects of the drug, strontium ranelate) may be effective when taken at night at least 4 hours after consumption of calcium.

    Strontium deposits in newly forming bone, where it incorporates into apatite crystals inside trabecular bone rather than cortical bone, most likely because cortical bone has a much slower turnover rate than trabecular bone. (The human skeleton is composed of approximately 80% cortical and 20% trabecular bone. Cortical bone is the hard outer shell of our bones, while trabecular bone is the more active, spongy, interior portion.)

    Moise H, Chettle DR, Pejović-Milić A. Monitoring bone strontium intake in osteoporotic females self-supplementing with strontium citrate with a novel in-vivo X-ray fluorescence based diagnostic tool. Bone. 2014 Apr;61:48-54. doi: 10.1016/j.bone.2014.01.002. Epub 2014 Jan 14. PMID: 24434614
    Wohl GR, Chettle DR, Pejović-Milić A, et al. Accumulation of bone strontium measured by in vivo XRF in rats supplemented with strontium citrate and strontium ranelate. Bone. 2013 Jan;52(1):63-9. doi: 10.1016/j.bone.2012.09.002. Epub 2012 Sep 17. PMID: 22995463

    Could it be harmful to have such high strontium levels as these articles suggest happens with the participants in the clinical trials over the years?

    Although supplemental strontium does continue to become part of the bone matrix for as long as has been studied in the research (5 years now), it does not negatively affect bone mineralization or bone quality. In fact, strontium not only increases the proliferation of osteoblast precursor cells, their differentiation into mature osteoblasts, collagen type I synthesis and bone matrix mineralization, but also inhibits the differentiation and activation of osteoclasts. Both sets of actions support the development of new bone and improved bone quality.

    Research conducted on human hip bone tissue (iliac crest specimens from postmenopausal osteoporotic women treated with strontium for 36 months) found a small number of calcium ions were replaced by strontium ions in the hydroxyapatite crystals in newly formed bone — a substitution of up to one atom in every one hundred of calcium atoms being replaced by a strontium atom — but the thickness and length of the bone mineral crystals were not affected, and there was no indication of a change in human bone tissue quality.

    Li C, Paris O, Siegel S, et al. Strontium is incorporated into mineral crystals only in newly formed bone during strontium ranelate treatment.J Bone Miner Res. 2010 May;25(5):968-75. doi: 10.1359/jbmr.091038. PMID: 19874195
    Roschger P, Manjubala I, Zoeger N, et al. Bone material quality in transiliac bone biopsies of postmenopausal osteoporotic women after 3 years of strontium ranelate treatment. J Bone Miner Res. 2010 Apr;25(4):891-900. doi: 10.1359/jbmr.091028. PMID: 20437609
    Moise H, Chettle DR, Pejović-Milić A. Monitoring bone strontium intake in osteoporotic females self-supplementing with strontium citrate with a novel in-vivo X-ray fluorescence based diagnostic tool. Bone. 2014 Apr;61:48-54. doi: 10.1016/j.bone.2014.01.002. Epub 2014 Jan 14. PMID: 24434614

    Is there a maximum level of safe strontium in bones?

    Because such a small amount of strontium is absorbed into bone when calcium intake is adequate, this is not of concern. Our bodies can only absorb a certain amount of calcium or strontium each day, and calcium is preferentially absorbed over strontium. If you are consuming the 1,200 milligrams of calcium recommended for women aged 51 and older, your body will naturally limit the amount of strontium that is absorbed.

    The majority of the published research on strontium discusses studies conducted using the drug, strontium ranelate, which, as I’ve written about at length, has numerous adverse cardiovascular and immunological effects, unlike natural forms of supplemental strontium, which have never been shown to cause any adverse side effects. However, the strontium ranelate research is useful for responding to this question since it is agreed in the research that there is no evidence to suggest that strontium ranelate is differently absorbed into bone or retained in bone compared to any other strontium salt, i.e., compared to strontium citrate.

    In the research studying the effects of strontium ranelate on osteoporotic women, in which study length averages between 3–5 years, the resulting replacement of calcium by strontium is a substitution of no more than one atom in every one hundred of calcium being replaced by a strontium atom – in other words, a very tiny amount. Only one human study has ever reported an adverse effect from too much strontium being deposited in bone: a paper published in 1996 reported an increased incidence of rickets in children in the Sivas province of Turkey due to very high levels of strontium in the soil and a low intake of calcium there. The recommendation made to prevent this: calcium supplements.
    Ozgür S, Sümer H, Koçoğlu G. Rickets and soil strontium. Arch Dis Child. 1996 Dec;75(6):524-6. PMID: 9014608 This is why you should err on the side of safety and always consume twice as much calcium as strontium.

    Be well,

    – Lara

  3. Melinda Spirk

    February 12, 2017 , 12:38 pm

    Hi Lara,

    My latest bottle of Strontium Citrate has a new warning label that states, “This product contains chemicals known to the State of California to cause cancer and birth defects or other reproductive harm.” I looked up strontium on their list, but it wasn’t mentioned; however, titanium dioxide, mentioned in the “other ingredients” area on the bottle, was. So, what’s your take on this? Should I ignore the warning and keep taking it, or is it cause for concern? Thanks for your help!

  4. Monica

    February 14, 2017 , 9:52 am

    Hi Melinda,
    The label is most likely referring to Titanium Dioxide as it is a known potential carcinogen. You can see the health concerns for Titanium Dioxide here: https://www.ewg.org/skindeep/ingredient/706561/TITANIUM_DIOXIDE/
    Warning labels like that should not be ignored lightly. Ideally, you should look for a Strontium Citrate product that does not have unnecessary additives like this. Strontium Boost (AlgaeCal’s Strontium Citrate product) is only strontium citrate, nothing else – no additives.

    – Monica @ AlgaeCal

  5. Marthie Gardner

    November 15, 2017 , 8:14 am

    I notice that none of the sources listed are more current than 2014. Can you recommend more current sources of material relating specifically to Strontium Citrate and its benefits and any negative side-effects.

    Thank you

  6. Monica

    November 16, 2017 , 7:22 am

    Hi Marthie,

    Lara has written a comprehensive article on Strontium here: https://blog.algaecal.com/the-truth-about-strontium-supplements-side-effects-dexa-results-efficacy-and-more/ and has recently updated it with newer references this past summer as well. Hope that helps!

    – Monica

  7. Laura

    April 8, 2018 , 8:42 am

    Can you take extra magnesium tabs along side your 680 mill of strontium at night?
    I’ve always taken extra magnesium at bedtime (in addition to the magnesium already in algaecal) that I take at breakfast and then again at lunch with meals.
    Also can you take extra D-3 with the strontium at night?
    So my question is: should strontium be taken ALONE before bedtime?

    Thank you,
    Laura

  8. Jenna AlgaeCal

    April 13, 2018 , 2:20 pm

    Hi Laura,

    Great question! Yes, you can absolutely take magnesium and vitamin D3 with the Strontium Boost at bedtime. We’re glad to see you were able to discuss this with one of our Bone Health Consultants as well! If you have any other questions let us know 🙂

    – Jenna @ AlgaeCal

This article features advice from our industry experts to give you the best possible info through cutting-edge research.

Lara Pizzorno
MDiv, MA, LMT - Best-selling author of Healthy Bones Healthy You! and Your Bones; Editor of Longevity Medicine Review, and Senior Medical Editor for Integrative Medicine Advisors.,
Dr. Liz Lipski
PhD, CNS, FACN, IFMP, BCHN, LDN - Professor and Director of Academic Development, Nutrition programs in Clinical Nutrition at Maryland University of Integrative Health.,
Dr. Loren Fishman
MD, B.Phil.,(oxon.) - Medical Director of Manhattan Physical Medicine & Rehabilitation and Founder of the Yoga Injury Prevention Website.,
Prof. Didier Hans
PHD, MBA - Head of Research & Development Center of Bone Diseases, Lausanne University Hospital CHUV, Switzerland,