Ingredients
Strontium is a naturally occurring mineral present in water and food. Trace amounts of strontium are found in the human skeleton. Strontium has an affinity for bone and is taken up at the bone matrix crystal surface.
The influence of strontium on bone metabolism has been researched since the 1950's. Recent studies show that strontium positively affects bone metabolism to promote bone formation and decrease bone resorption, leading to normalized bone density. Strontium citrate supplies strontium that is safe and suitable for consumption as a dietary supplement.
(This form of strontium is entirely different from the radioactive "strontium-90" formed by nuclear fission.)
Benefits
Helps maintain strong, healthy bones
IN VITRO AND ANIMAL STUDIES:
Strontium is a bone-seeking mineral incorporated by ionic substitution for calcium onto the crystal surface of bone. In the test-tube (in vitro), strontium inhibits the activity of osteoclasts, bone cells that break down bone, or "resorb" bone as part of the normal bone remodeling process.
The effect of strontium, in the form of strontium ranelate (a salt of strontium and ranelic acid), was studied in monkeys over a six-month period. Strontium altered the remodeling of bone in the monkeys, resulting in decreased bone resorption with a concomitant maintenance of bone formation.
A trend toward increased volume of osteoid, the organic matrix of bone, was observed, although this was not associated with defects in bone mineralization. In another animal study, monkeys fed strontium at high doses for six weeks showed a marked increase in bone strontium content. No harmful effects on bone mineral chemistry or structure occurred.
At low doses, strontium has been shown to increase the number of bone forming sites in thighbones of adult rats, without adverse effects on the mineral content of bone or mineralization of the organic bone matrix. Strontium was shown to reverse bone loss induced by estrogen deficiency in rats. Clinical Trials Human clinical trials have examined the effect of strontium on bone in post-menopausal women. In the dose-ranging (Phase 2) PREVOS trial, women in early menopause were administered strontium ranelate or a placebo for two years. Strontium ranelate was given at daily doses of 125 mg, 500 mg or 1 gram. (Total weight of compound; strontium plus ranelic acid).
Compared to women in the placebo group, who lost bone, women ion strontium at the 1 gram dose showed statistically significant increases in bone mineral density (BMD) of the hip, thigh and lumbar spine. Biochemical markers of bone formation, such as serum alkaline phosphatase, increased.
No effect on markers of bone resorption was observed, leading to the conclusion that strontium ranelate, as the 1 gram daily dose, increased bone formation without decreasing bone resorption proportionally. It was concluded that 1 gram per day is the minimum effective daily dose of strontium ranelate in these women. In another Phase 2 trial (STRATOS trial), 353 post-menopausal women with osteoporosis, who had experienced at least one spinal fracture, took strontium ranelate for two years at daily doses of 500 mg, 1 gram or 2 grams.
Women on the 2-gram dose showed a significantly greater increase in lumbar spine BMD than those on placebo. The number of subjects who had new spinal deformities was significantly reduced. As in the PREVOS trial, serum levels of alkaline phosphatase, a marker of bone formation, increased while markers of bone resorption (breakdown) decreased.
The overall conclusion is that the minimum effective daily dose of strontium ranelate (whole compound) is 1 gram in early post-menopausal non-osteoporotic women and 2 grams in post-menopausal women with osteoporosis. Phase 3 efficacy studies on strontium ranelate have been conducted on 1649 subjects in 12 countries. These studies began with an open-run (non-controlled) study period in which subjects took calcium and Vitamin D supplements to normalize their blood levels of these nutrients. Following this, two parallel groups were administered 3 grams daily of strontium ranelate of placebo for 3 years. The subjects continued to take calcium and Vitamin D during the study. In subjects on strontium ranelate, BMD increased in the lumbar vertebrae by 14.4 percent and in the thighbone by 8.3 percent. The number and risk of vertebral fractures decreased.
Source: Doctor's Best
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Scientific References
- Shorr E, Carter AC. The usefulness of strontium as an adjuvant to calcium in the re-mineralization of the skeleton in man. Bull Hosp Joint Dis 1952; 13: 59-66.
- Dahl SG, Allain P, Marie PJ., et. al. Incorporation and distribution of strontium in bone. Bone 2001; 28(4): 446-53.
- Baron R., Tsouderos Y. In vitro effects of S12911-2 on osteoclast function and bone marrow macrophage differentiation. Eur J Pharmacol 2002; 450: 11-17.
- Buehler J, Chappuis P, Saffar JL., et. al. Strontium ranelate inhibits bone resorption while maintaining bone formation in alveolar bone in monkeys (Macaca fascicularis) Bone 2001; 29(2): 176-79.5.
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