Should you
take strontium citrate if you have hypercalciuria (high urine calcium) or a
history of kidney stones? Perhaps you should not. A recent study identified
strontium in all calcium-based stones, present as strontium apatite. This
finding may be critical since apatite is thought to be the initial nidus for
calcium stone formation. Strontium is found in small amounts in food and water.
The paper does not state if any of the stone formers had taken strontium
supplements. I wrote to one of the researchers, the contact person, to find out
if he knew the source of the strontium found in the kidney stones. He answered
that he did not know if those with elevated strontium in their diet or
those with strontium intake (tablets) were the ones with elevated strontium in
their stones. What follows is the abstract from the research paper,
“Strontium Substitution for Calcium in Lithogenesis.” Use the link at the end
to read the entire paper.
Purpose
Strontium has chemical similarity to
calcium, which enables the replacement of calcium by strontium in
biomineralization processes. Incorporating strontium into human bone and teeth
has been studied extensively but little research has been performed of the
incorporation of strontium into urinary calculi. We used synchrotron based
x-ray fluorescence and x-ray absorption techniques to examine the presence of
strontium in different types of human kidney stones.
Materials
and Methods
Multiple unique human stone samples
were obtained via consecutive percutaneous nephrolithotomies/ureteroscopies. A
portion of each stone was sent for standard laboratory analysis and a portion
was retained for x-ray fluorescence and x-ray absorption measurements. X-ray
fluorescence and x-ray absorption measurements determined the presence, spatial
distribution and speciation of strontium in each stone sample.
Results
Traditional kidney stone analyses
identified calcium oxalate, calcium phosphate, uric acid and cystine stones.
X-ray fluorescence measurements identified strontium in all stone types except
pure cystine. X-ray fluorescence elemental mapping of the samples revealed
co-localization of calcium and strontium. X-ray absorption measurements of the
calcium phosphate stone showed strontium predominately present as strontium
apatite.
Conclusions
Advanced x-ray fluorescence imaging
identified strontium in all calcium based stones, present as strontium apatite.
This finding may be critical since apatite is thought to be the initial nidus
for calcium stone formation. Strontium is not identified by standard laboratory
stone analyses. Its substitution for calcium can be reliably identified in
stones from multiple calcium based stone formers, which may offer opportunities
to gain insight into early events in lithogenesis.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4124908/
