Another concern is that strontium can inflate bone density readings because the element has a higher atomic weight than calcium, which it replaces in bone (thus bones may appear stronger than they really are). Researchers usually adjust for this when reporting bone density in strontium studies.
http://www.berkeleywellness.com/supplements/minerals/article/new-supplement-old-bones
1 Though most studies have focused on women, there’s some evidence that strontium helps men too. In a 2013 study in the Journal of Clinical Endocrinology & Metabolism, men with osteoporosis who took strontium ranelate for two years had evidence of increased bone density in the spine and hip.  For joints.
http://www.berkeleywellness.com/supplements/minerals/article/new-supplement-old-bones
Strontium, a common metallic element, is not classified as a nutrient, but the human body can absorb it and use it as if it were calcium. Like calcium, it always comes bound to other elements. Most supplements contain strontium citrate. Another form, strontium ranelate, is patented and sold only as a prescription drug for osteoporosis in Europe and Australia. This form has been shown in clinical trials to boost bone mineral density and reduce fractures.
http://www.berkeleywellness.com/supplements/minerals/article/new-supplement-old-bones
Its compounds burn with a crimson flame and are used in fireworks. The radioisotope strontium-90, with a half-life of 28.1 years, is used in nuclear power sources and is a hazardous nuclear fall-out product. Symbol: Sr; atomic no: 38; atomic wt: 87.62; valency: 2; relative density: 2.54; melting pt: 769°C; boiling pt: 1384°C. [C19: from New Latin, from strontian]
http://www.thefreedictionary.com/strontium
Symbol Sr A soft, silvery metallic element that is an alkaline-earth metal and occurs naturally only as a sulfate or carbonate. One of its isotopes is used in the radiometric dating of rocks. Because strontium salts burn with a red flame, they are used to make fireworks and signal flares. Atomic number 38.
http://www.thefreedictionary.com/strontium
Strontium has been safely used as a medicinal substance for more than a hundred years. It was first listed in Squire’s Companion to the British Pharmacopoeia in 1884. Subsequently, strontium was used therapeutically in the United States and Europe.
http://drhoffman.com/article/strontium-for-bone-health-2/
In clinical research strontium gluconate was absorbed better than strontium carbonate. It is my clinical opinion that strontium citrate is absorbed better than the other forms of this mineral. Remember that strontium is very closely related to calcium. They both utilize the same carrier protein for transport. Calcium will win this tug of war effortlessly. The take home message is to take strontium 4 hours away from calcium (preferably other minerals as well) before bed. Currently, I dose strontium at 681mg in one dose prior to bed (each strontium citrate capsule contains 227mg of pure strontium citrate = 3 capsules) on an empty stomach (defined as 2 hours after a meal).
http://drhoffman.com/article/strontium-for-bone-health-2/
Aside from when I was studying the periodic table of elements, my knowledge of strontium occurred while reading Dr. Wright’s Guide to Healing With Nutrition, a wonderful book written in 1971 as a treatise for medical students that ended up being a popular press book.
http://drhoffman.com/article/strontium-for-bone-health-2/
Strontium-90 (90Sr) has a half-life of 28 years. It is a product of nuclear fallout and presents a major health problem. Strontium titanate is an interesting optical material as it has an extremely high refractive index and an optical dispersion greater than that of diamond.
http://www.webelements.com/strontium/
Strontium: the essentials. Strontium does not occur as the free element. Strontium is softer than calcium and decomposes water more vigorously. Freshly cut strontium has a silvery appearance, but rapidly turns a yellowish colour with the formation of the oxide. The finely divided metal ignites spontaneously in air.
http://www.webelements.com/strontium/
what is strontium?
Strontium is a common metallic element but the human body can absorb it and use it as if it were calcium.