Accumulation of bone strontium measured by in vivo XRF in rats supplemented with strontium citrate and strontium ranelate

Wohl GR, Chettle DR, Pejović-Milić A, Druchok C, Webber CE, Adachi JD, Beattie KA

Bone 2013

Strontium ranelate is an approved pharmacotherapy for osteoporosis in Europe and Australia, but not in Canada or the United States. Strontium citrate, an alternative strontium salt, however, is available for purchase over-the-counter as a nutritional supplement. The effects of strontium citrate on bone are largely unknown.

The study's objectives were (1) to quantify bone strontium accumulation in female Sprague Dawley rats administered strontium citrate (N=7) and compare these levels to rats administered strontium ranelate (N=6) and vehicle (placebo) (N=6) over 8 weeks, and (2) to verify an in vivo X-ray fluorescence spectroscopy (XRF) system for measurement of bone strontium in the rat. Daily doses of strontium citrate and strontium ranelate were determined with the intention to achieve equivalent amounts of elemental strontium. However, post-hoc analyses of each strontium compound conducted using energy dispersive spectrometry microanalysis revealed a higher elemental strontium concentration in strontium citrate than strontium ranelate.

Bone strontium levels were measured at baseline and 8 weeks follow-up using a unique in vivo XRF technique previously used in humans. XRF measurements were validated against ex vivo measurements of bone strontium using inductively coupled plasma mass spectrometry. Weight gain in rats in all three groups was equivalent over the study duration. A two-way ANOVA was conducted to compare bone strontium levels amongst the three groups. Bone strontium levels in rats administered strontium citrate were significantly greater than in rats administered strontium ranelate and vehicle. ANCOVA analyses were performed with Sr dose as a covariate to account for differences in strontium dosing. The ANCOVA revealed differences in bone strontium levels between the strontium groups were not significant, but that bone strontium levels were still very significantly greater than vehicle.

https://www.facebook.com/pages/Strontium-for-Osteoporosis/462179087156676

http://www.ncbi.nlm.nih.gov/pubmed/22995463

Strontium Basics

What is the recommended amount of strontium?

The amount of a strontium salt (e.g. strontium citrate) for prevention of bone loss in early postmenopausal non-osteoporotic women is roughly 1 gram per day to get about 340 mg of elemental strontium.

The amount of a strontium salt for treatment of postmenopausal osteoporosis is roughly 2 grams per day to get about 680 mg of elemental strontium.

When should you take strontium as per time of day and how far apart from calcium?

You can take strontium at any time as long as you take it at least 2-3 hours after taking food, milk or milk products, or calcium supplements. Calcium competes with strontium for absorption; so, you will absorb less strontium if you take calcium and strontium too close together. You will absorb strontium better on an empty stomach. I take my strontium at night shortly before bedtime. Take it when it is most convenient for you.

In what ratio to calcium should you take strontium?

You do not need to worry about a ratio of calcium to strontium. The amount of calcium you need, whether you take strontium or not, depends on your age and sex. Adult men (51-70 years old) need 1000 mg daily. Adult women (51-70 years old) need 1200 mg per day. These are total amounts of calcium. So, what you need to do first is figure out how much calcium you are getting from food, and then supplement the rest, if needed. You should strive to get all, or most, of your calcium from food.