Health / Medical / Nutrition / Osteoporosis / January 10, 2012

The Truth about Strontium Supplements, Side Effects, DEXA Results, Efficacy and More

Don’t let misleading commentaries prevent you from reaping the bone-building benefits of strontium!

Having now reviewed the published research conducted on both natural strontium salts and strontium ranelate, I can confidently assure you that natural forms of strontium can provide a safe and highly effective contribution to the health – both the density and the tensile quality — of your bones.

What are the scare tactics being used to dissuade us from utilizing strontium? It is claimed @ that:

  • Strontium has a long list of undesirable side-effects, commonly ranging from nausea to skin irritation, and less often (fortunately), blood clots and fainting.
  • Since strontium is denser than calcium, it is difficult to assess actual bone improvement in a DEXA scan.
  • Several studies conclude that strontium causes the outer cortical bone to become thicker, actually reducing tensile strength. This increases the risk of fractures.
  • Strontium competes with calcium absorption.

When confronted with the facts in the research, these apparent threats to one’s health when taking supplemental strontium either simply do not hold up or are revealed to be no problem at all. Let’s take a closer, research-based look at each of them.

Natural forms of strontium, when consumed in lesser amounts than calcium, are very safe

The side-effects attributed to blanket-fashion to all available supplemental forms of strontium have been seen with strontium ranelate, but not with any natural strontium salt, such as strontium citrate.

The only negative effects seen with natural strontium salts occurred in 1 animal study conducted in 1994 and 1 human study conducted in 1996.

In the animal study, immature lab rats (whose bones were still developing) were deliberately given a low calcium diet and supplemented with high doses of strontium. Not surprisingly, since calcium is the major mineral found in normal bone, and these animals were calcium-deprived, the rats developed ricket-like bone deformities.[1]

The human study was conducted in Turkey in 1996. [2] Before complete data analysis, it looked like there was a higher incidence of bone malformations (i.e., rickets) in young children in areas of Turkey with very high strontium concentrations in the soil. However, when the question of whether the children had been breastfed was taken into account, the risk for rickets no longer differed between people living in high strontium areas compared to those with low strontium. Why? Because breast milk provides the calcium and protein that prevents excessive incorporation of strontium into bone.  In other words, only when much more strontium is consumed than calcium do bone formation abnormalities, e.g., rickets, occur.

According to the Centers for Disease Control’s Agency for Toxic Substances and Disease Registry, which published a 161-page report [3] on the health effects of natural forms of strontium, e.g., strontium citrate:

“There is no direct evidence that strontium is toxic to humans, but there is suggestive epidemiological evidence that the oral toxicity observed at high doses in juvenile laboratory animals may pertain to humans under special circumstances [here, they are referring to the 2 studies discussed immediately above, which is why their following sentence emphasizes the importance of adequate calcium, phosphorus and vitamin D]. At low exposure levels, ingestion of stable strontium poses no harm to organisms with access to adequate calcium, phosphorus, and vitamin D. At higher exposure levels, especially under conditions of inadequate calcium, phosphorus, and vitamin D, stable strontium will interfere with normal bone development, causing ‘strontium rickets’ of variable severity.”

Adverse Side-effects Are Seen ONLY with Strontium Ranelate – Natural Strontium Salts, Like Strontium Citrate are Safe

In contrast, following on the heels of data collected in a number of other studies,[4],[5] the most recent research — a three year study conducted in France whose results were published in October 2011 [6] — confirms that the patented unnatural form of strontium, strontium ranelate has a number of potential side-effects, at least two of which are very serious: an increased risk for venous thromboembolism (VTE, deep vein blood clots) and DRESS syndrome.

Overall, the likelihood that you will be among the ones affected can be argued to be small – although a review of the research on strontium ranelate published in 2005 states “Strontium [ranelate] caused a 50% increase in the risk of venous thromboembolism (including pulmonary embolism).”[7]

In the health information provided for medical professionals,[8] Servier, the pharmaceutical company with the patent on strontium ranelate (trade name ProtelosTM) states:

“In phase III studies, the annual incidence of venous thromboembolism (VTE) observed over 5 years was approximately 0.7%, with a relative risk of 1.4 (95% CI = [1.0 ; 2.0]) in strontium ranelate treated patients as compared to placebo.”

What does this mean in plain English?  Over a 5-year period in the Phase III studies, each year, 0.7% of those taking strontium ranelate developed VTE. Saying that those taking strontium ranelate had a relative risk for VTE of 1.4 compared to placebo means that strontium ranelate increased risk for VTE by 40%. Strontium citrate has never been found to increase risk of VTE.

The other serious side-effect for which people taking strontium ranelate are at increased risk is DRESS syndrome. (Strontium citrate has never been found to increase risk of DRESS syndrome.) Symptoms of DRESS syndrome typically begin 1-8 weeks after exposure to the offending patent medication. Classic symptoms include widespread rash, fever, and involvement of one or more internal organs. Approximately 50% of patients will have hepatitis (liver inflammation), 30% will have eosinophilia (high levels of white cells in the blood indicating immune system activation), 10% will have nephritis (inflamed kidneys), and 10% will have pneumonitis (inflamed lungs). DRESS syndrome is often severe and can result in death if not diagnosed early – thus the warnings to see your doctor immediately if you develop a rash after taking strontium ranelate.

In his excellent YouTube presentation on strontium, Dr. Brunnel, discussing strontium ranelate, notes that “99-93% of the ranelic acids is excreted unchanged within a week.” I have a question and a comment to make in regards to this. My question is “What has happened to the up to 7% of ranelic acid that is NOT excreted from the body? What is it doing?” And my comment is that it is important to realize that just because something is excreted does not mean it did not do anything on its way through the body. Ranelic acid is a new-to-nature, never seen by the human body, compound. Simply assuming it is inert and is not going to do anything inside the human body is questionable – and the side effects associated with the use of strontium ranelate suggest this assumption is incorrect.

The latest review of the evidence confirming strontium ranelate may produce potentially lethal adverse effects has just been published in Prescrire International,  March 21, 2012. The title of this review? “Strontium ranelate: too many adverse effects: Do not use.”[9]

Since VTE and DRESS syndrome are likely to result in death, why expose yourself to any increased risk for them when you can take strontium citrate, proven to be a natural, safe and effective form of strontium?


Strontium citrate is not only safe, but delivers an important added benefit to your bones

While working my way through the last 30 years of research on strontium, I mentioned to my husband, Dr. Joe Pizzorno, that I was looking into the safety and effectiveness of natural forms of strontium versus the patented drug, strontium ranelate. His response was that the “citrate” form of natural strontium, specifically, should be the best.

The reason for this is that – unlike ranelic acid, a weird hydra-headed molecule never before seen by the human body – citrate actually helps make the body’s pH more alkaline. This is very important because it helps prevent the low-grade metabolic acidosis – an overly acidic pH –that is caused by a diet too high in protein, is quite common in the U.S. and Canada, and causes bone loss. In fact, this is such an important health issue that Joe recently wrote an article about it, which was published in the British Journal of Nutrition in April 2010.[10]

Data from US Third National Health and Nutrition Examination Survey (NHANES III) shows that the average American diet (i.e., the typical Western diet) is acid-producing and results in a state of chronic low-grade metabolic acidosis. This increases bone loss because an acid pH is a strong activator of osteoclasts, the cells that break down bone. In this case, the osteoclasts’ activity is ramped up because when bone is broken down, calcium is released, and calcium restores a more alkaline pH.

Taking strontium, specifically in the form of strontium citrate, will help you maintain a more alkaline pH.

Strontium impacts DEXA results

It is true that strontium affects DEXA results. Strontium has a larger atomic number (Z=38) than calcium (Z=20). This causes the DEXA BMD reading to be overestimated.

Here are the facts on this from the most recently published paper discussing this issue: “If 1% of calcium atoms in hydroxyapatite are replaced by strontium, BMD measurements are increased by 10% although the net mass of bone mineral increases by only 0.5%.[11]

The key issue here, however, is “What is the practical importance of this for you?” What does this say about strontium’s ability to help you maintain healthy bones and prevent fractures?

Bottom line: Strontium increases BMD. Well, what’s wrong with that?  Is the DXA still useful? Absolutely, an improvement in your DXA shows that you are responding positively to treatment with strontium, that your BMD is increasing, and your risk for fracture is decreasing.[12]

So, yes, BMD as measured by DXA will be over-estimated in people taking strontium, but what really matters here is that strontium treatment increases bone mass and reduces fracture risk. DXA is useful in that it shows whether you are responding (absorbing strontium well), and a better DXA score still correlates with lower risk for fractures.

strontium citrate supplements

Strontium does NOT increase risk for fractures – quite the opposite

If one is going to make a claim like “Several studies conclude that strontium causes the outer cortical bone to become thicker, actually reducing tensile strength. This increases the risk of fractures,” it should be backed up with footnotes citing these studies, and they should be bona fide, peer-reviewed papers accessible on PubMed.

Since no references were provided to substantiate this claim, I ran a search on PubMed for these “several studies” and could find nary a one.  What I found were papers showing the exact opposite.

In animal studies (discussed in the 161-page report on strontium by the Agency for Toxic Substances and Disease Registry cited above), strontium has been proven to improve BMD without altering bone stiffness.

Numerous papers (way too many references to list them all – I provide many more in Your Bones — here are just a few of the significant papers:[13],[14],[15]) reporting the results of the SOTI and TROPOS trials — large, multi-center human trials that together involved ~7,000 postmenopausal women (many of whom had already had an osteoporotic fracture when they began treatment with strontium) — show strontium greatly reduces risk of vertebral, femur and hip fractures in as little as 1 year. Other studies have produced similar results, but SOTI and TROPOS are the largest, and have been running the longest.

A key aspect of the SOTI (Spinal Osteoporosis Therapeutic Intervention) and TROPOS (Treatment of Peripheral Osteoporosis Study) trials was the advanced age of most of the subjects compared with many previous osteoporosis trials:  23% of the combined study populations were aged 80 years or older at enrolment. In women older than 80 years, strontium produced a 55% reduction for vertebral fractures over the first year of treatment and a 32% reduction over 3 years.

In the SOTI trial, which included 1,649 patients whose average age was 70 years, at the end of the first year, women taking strontium had a 49% lower risk of a new radiographic [seen on x-ray] vertebral fracture compared to women given a placebo. The risk of a clinically symptomatic vertebral fracture was 52% lower. After 3 years, the strontium group had a 41% lower risk of a new radiographic fracture, and the incidence of clinically symptomatic vertebral fractures was 38% lower. When the 4-year data were reported, they showed a 33% reduction in radiographic vertebral fractures.

In the TROPOS study, an even larger trial with 5,091 patients whose average age was 77 years, strontium produced a risk reduction of 16% in vertebral fractures and a 19% reduction in risk of non-vertebral fractures (e.g., hip, femur, wrist, ribs, etc.) In TROPOS, in the subgroup of women at highest risk of fracture (women 74 years of age or older who had a low femoral neck BMD score), strontium reduced the risk of hip fracture 36%. Over 3 years, the reduction in vertebral fracture risk was 39% and was similar even for patients who had already had a vertebral fracture when the study began. The 5-year data showed a 24% reduction in vertebral fracture risk.

The most recent paper, published November 2011, reports the results of 10 years of strontium use in the postmenopausal osteoporotic women who, after participating in the SOTI and TROPOS studies for 5 years, were invited to enter a 5-year extension, during which they received strontium ranelate at a dose of 2 grams/day.  The results: vertebral fracture risk was reduced by 31%, nonvertebral fracture risk by 27%, major nonvertebral fracture risk by 33%, and hip fracture risk by 24%.[16]

Obviously, these results run counter to the claim that strontium increases fracture risk!

Strontium competes with calcium for absorption

Yes, and calcium wins. “The simultaneous intake of strontium and calcium remarkably reduces the bio-availability of strontium.”[17]

For this reason, it is best to take strontium supplements and calcium at different times of day to get the most benefit.

Strontium citrate has much to offer your bones!

I hope this discussion of the research findings helps put your mind at ease regarding strontium. Strontium has much to offer your bones! We now know that strontium not only lessens osteoclast production and bone resorption (so unlike the bisphosphonates, e.g. Fosamax™, Boniva™, or the latest osteoporosis drug on the block, denosumab, e.g. Prolia™, strontium does not prevent healthy bone remodeling), but also boosts osteoblast production and bone synthesis.[18] What’s not to like about that?

No adverse effects have been associated with the natural forms of strontium when calcium and vitamin D are also supplied.

The only precautions are: take more calcium than strontium, for best results take strontium at a different time of day from when you take your calcium, and take a natural form of strontium – all of which you will automatically be doing if you follow the AlgaeCal protocol.


  1. ^Neufeld EB, Boskey AL. Strontium alters the complexed acidic phospholipid content of mineralizing tissues. Bone. 1994 Jul-Aug;15(4):425-30. PMID: 7917582
  2. ^Ozgur S, Sumer H, Kocoglu G. Rickets and soil strontium. Arch Dis Child. 1996 Dec;75(6):524-6. PMID: 9014608
  3. ^Centers for Disease Control’s Agency for Toxic Substances and Disease Registry Health Effects of Strontium report accessible @
  4. ^Osborne V, Layton D, Perrio M, et al. Incidence of venous thromboembolism in users of strontium ranelate: an analysis of data from a prescription-event monitoring study in England. Drug Saf. 2010 Jul 1;33(7):579-91. doi: 10.2165/11533770-000000000-00000. PMID: 20553059
  5. ^Le Merlouette M, Adamski H, Dinulescu M, et al. Strontium ranelate-induced DRESS syndrome. Ann Dermatol Venereol. 2011 Feb;138(2):124-8. Epub 2010 Dec 16. PMID: 21333824
  6. ^Jonville-Bera AP, Autret-Leca E. Adverse drug reactions of strontium ranelate(Protelos(®) in France).Presse Med. 2011 Oct;40(10):e453-62. Epub 2011 Aug PMID: 21885232
  7. ^No authors listed. Strontium: new drug. Postmenopausal osteoporosis: too many unknowns. Prescrire Int. 2005 Dec;14(80):207-11. PMID: 16397977
  8. ^
  9. ^No authors listed. Strontium ranelate: too many adverse effects (continued) Do not use. Prescrire Int. 2012 Mar;21(125):72. PMID: 22428195
  10. ^Pizzorno J, Frassetto LA, Katzinger J. Diet-induced acidosis: is it real and clinically relevant? Br J Nutr. 2010 Apr;103(8):1185-94. Epub 2009 Dec 15.
  11. ^Bärenholdt O, Kolthoff N, Nielsen SP. Effect of long-term treatment with strontium ranelate on bone strontium content. Bone. 2009 Aug;45(2):200-6. Epub 2009 Apr 17. PMID: 19376283
  12. ^Belissa-Chatelain P, Dupin-Roger I, Cournarie F, et al. Re: “Effect of long-term treatment with strontium ranelate on bone strontium content” by Bärenholdt et al. (Bone, 2009). Bone. 2009 Nov;45(5):1024-5; author reply 1026-7. Epub 2009 Jul 17. PMID: 19616656
  13. ^Meunier PJ, Roux C, Ortolani S, et al. Effects of long-term strontium ranelate treatment on vertebral fracture risk in postmenopausal women with osteoporosis. Osteoporos Int. 2009 Oct;20(10):1663-73. Epub 2009 Jan 20. PMID: 19153678
  14. ^Reginster JY, Seeman E, De Vernejoul MC, et al. Strontium ranelate reduces the risk of nonvertebral fractures in postmenopausal women with osteoporosis: Treatment of Peripheral Osteoporosis (TROPOS) study. J Clin Endocrinol Metab. 2005 May;90(5):2816-22. Epub 2005 Feb 22. PMID: 15728210
  15. ^Reginster JY, Felsenberg D, Boonen S, et al. Effects of long-term strontium ranelate treatment on the risk of nonvertebral and vertebral fractures in postmenopausal osteoporosis: Results of a five-year, randomized, placebo-controlled trial. Arthritis Rheum. 2008 Jun;58(6):1687-95. PMID: 18512789
  16. ^Reginster JY, Kaufman JM, Goemaere S, et al. Maintenance of antifracture efficacy over 10 years with strontium ranelate in postmenopausal osteoporosis. Osteoporos Int. 2011 Nov 29. [Epub ahead of print] PMID: 22124575
  17. ^Reginster JY. Strontium ranelate in osteoporosis. Curr Pharm Des. 2002;8(21):1907-16. PMID: 12171530
  18. ^Bonnelye E, Chabadel A, Saltel F, et al. Dual effect of strontium ranelate: stimulation of osteoblast differentiation and inhibition of osteoclast formation and resorption in vitro. Bone. 2008 Jan;42(1):129-38. Epub 2007 Sep 12. PMID: 17945546