Strontium is a naturally occurring trace element chemically similar to calcium. It is found in small amounts in bone and water, and has been used medicinally at high doses (strontium ranelate) to increase bone density in osteoporosis. However, strontium ranelate was withdrawn from most markets due to cardiovascular concerns. Strontium in bone can interfere with DEXA bone density measurements, creating falsely reassuring results.
Blood strontium testing is used to monitor whether strontium supplementation is at a safe level, to detect excessive exposure, and to assess whether bone-building supplements containing strontium are causing accumulation. Very high strontium exposure from industrial sources or excessive supplementation can be toxic.
FAQs
Is strontium supplement safe for bones?
High-dose strontium supplementation does increase DEXA bone density scores, but this is partly an artefact — strontium in bone absorbs X-rays differently from calcium, making bone appear denser than it is. Evidence for actual fracture risk reduction from supplements is weak, and strontium ranelate (the pharmaceutical form) was restricted due to cardiovascular risks.
Does strontium interfere with DEXA scans?
Yes. Strontium in bone absorbs more X-rays than calcium, causing DEXA scanners to overestimate bone mineral density by up to 10-50% depending on the strontium level. If you take strontium supplements, inform the radiologist before DEXA scanning.
Is strontium-90 the same as dietary strontium?
No. Strontium-90 is a radioactive isotope produced by nuclear fission (from nuclear weapons and reactor accidents). It is chemically similar to stable strontium but is dangerous because it emits radiation and can accumulate in bone. Background strontium from food and supplements is stable and non-radioactive.
Should I take strontium supplements for osteoporosis?
Most specialist guidelines do not recommend high-dose strontium supplements for osteoporosis management given the DEXA interference and limited fracture evidence. PBS-listed medications with proven fracture reduction benefit are preferred.
