Strontium

    Researchedby:
    Daryl Nault

    Fact-checked

    by:

    Katie Jantz, Conni Covington
    Last Updated: October 24, 2024

    Strontium is a naturally occurring mineral found in our bodies. It shares some similarities with calcium, which explains why it’s touted for conditions like tooth sensitivity, osteoporosis, and general bone health.

    What is strontium?

    Strontium is a naturally occurring trace element that is chemically similar to calcium. However, because of their few differences (e.g., size), strontium and calcium aren’t biologically equivalent, and they can compete for absorption and utilization in the body.[13]

    A typical diet contains 2–4 mg of strontium per day, mostly from plant-based (grain and vegetable) sources.[15][14] However, estimates have ranged from 1.4–5.7 mg per day, too.[16] The amount of strontium in a given food source varies by the amount of strontium in the soil, which may explain the variability in intake estimates.[15][14]

    What other forms of strontium are used in medicine?

    What are strontium’s main benefits?

    The currently available evidence does not demonstrate the benefits of strontium formulations that can be obtained for oral supplementation over the counter. Though clinical evidence is lacking, the available preclinical evidence suggests that strontium could improve bone strength (preventing bone loss and fractures related to bone loss).[16][15][14]

    When used as an additive to toothpaste or creams and applied topically, strontium has been shown clinically to reduce dental and skin sensitivities or irritation.[17][5][6][16][2][3][4]

    What effect might strontium have on bone or dental health?

    What are strontium’s main drawbacks?

    Because of their similarities, strontium and calcium compete in the body. For example, strontium competes with calcium for absorption, notably in the intestines and renal tubules.[15] Calcium tends to be preferred physiologically, though, so taking the two minerals together may reduce the absorption and retention of strontium. Strontium absorption is reduced by phosphate and increased by vitamin D.[13] For these reasons, supplement labels will often recommend taking these supplements separately and also ensuring that adequate calcium is consumed.[1][14][15]

    As we age, how the body differentiates between strontium and calcium can vary. In early childhood, during bone development, excess exposure to strontium can impede bone growth and cause strontium-induced rickets. Though these risks are not as concerning for adults, strontium can still interfere with normal bone development when taken in circumstances where vitamin D, phosphorus, and calcium intakes are insufficient.[13][16]

    In observational evidence on hypertension in pregnancy, higher blood strontium levels were associated with hypertensive disorders, but a clear cause-and-effect relationship could not be determined.[18]

    How does strontium work?

    Bone strength is maintained through cycles of bone formation and resorption via specialized cells called osteoblasts (formation) and osteoclasts (resorption). When bone resorption starts to exceed bone formation, bone strength suffers, leading to conditions like osteoporosis.[19]

    When absorbed, almost all of the strontium ends up in bones, teeth, and joint structures.[16] Once incorporated into the bone, calcium and strontium appear to behave similarly.[15][14][16] Strontium may promote the new formation of bone by increasing the number of osteoblasts and preventing their destruction.[14][16]

    Though we still don’t have a complete understanding of how strontium works in the body, one possible mechanism may be that it works its way into bone cells to fill the gaps left by excessive resorption.[15][14] When used as a toothpaste additive, strontium is believed to work by blocking the exposed dentine tubules that produce dental hypersensitivity.[17][5][6]

    In some preclinical (animal) studies, strontium seems to reduce pro-inflammatory cytokines to reduce inflammation.[16] If the same anti-inflammatory activity occurs in humans, that could explain why it has shown some evidence of being useful for reducing skin irritation and itching as part of topical ointments.[2][3][4]

    What are other names for Strontium?

    Note that Strontium is also known as:

    • Elemental strontium
    • Strontium acetate
    • Strontium amino acid chelate
    • Strontium aspartate
    • Strontium carbonate
    • Strontium calcium ascorbate
    • Strontium citrate
    • Strontium chloride
    • Strontium gluconate
    • Strontium malate
    • Strontium nitrate
    • Strontium oxide
    • Strontium ranelate

    Dosage information

    Formulation: Strontium used to be a more common toothpaste additive to ease dental sensitivity. Over time it has fallen out of favor in the US and is being replaced by ingredients like potassium nitrate. Though there are some investigations into whether strontium chloride or nitrate may be useful in applications of skin sensitivities, these may also be difficult to find over the counter. In the US, strontium can be found in dietary supplements, most commonly as strontium citrate. Other forms of strontium sold over the counter as supplements include strontium chloride, strontium gluconate, strontium carbonate, strontium aspartate, and elemental strontium. Over the counter, strontium supplements are found in capsule, tablet, softgel, powder, and liquid forms.

    Range of dosages studied: Oral strontium supplements currently on the market in the US range from 0.01–2,000 mg per day.[1]

    For skin irritation and itching, strontium has been studied as a topical formulation that’s either 20% strontium nitrate or 4% strontium chloride, combined with other ingredients. For tooth hypersensitivity, pastes containing 2–10% strontium chloride or 8% strontium acetate have been studied.

    Effective Dosages:

    Skin Irritation/Itching

    Adults: Direct application of a topical ointment containing either 20% strontium nitrate or 4% strontium chloride, combined with other ingredients (e.g., hydrocortisone, diphenhydramine, glycolic acid).[2][3][4]

    Dental Sensitivity

    Adults: Toothpaste containing 8% strontium acetate or 2–10% strontium chloride, for use twice per day in normal brushing.[5][6][7][8][9][10][11][12]

    Other Considerations: For other conditions (osteoarthritis, osteoporosis, bone-fracture risk) strontium ranelate has been studied as a pharmaceutical agent. Strontium ranelate is used by prescription in Europe for treating osteoporosis, but it is not currently approved by the US FDA because of concerns of cardiovascular risk. High levels of strontium exposure have been associated with calcium, phosphorus, and vitamin D deficiencies.[13]

    For other forms of strontium as an oral, over-the-counter supplement, clinical evidence is lacking.

    Supplement labels often recommend taking strontium and calcium supplements separately (often spaced at least 2–4 hours apart).[1] This makes sense, because our ability to absorb strontium decreases when taken in conjunction with calcium.[13][14]

    Frequently asked questions

    What is strontium?

    Strontium is a naturally occurring trace element that is chemically similar to calcium. However, because of their few differences (e.g., size), strontium and calcium aren’t biologically equivalent, and they can compete for absorption and utilization in the body.[13]

    A typical diet contains 2–4 mg of strontium per day, mostly from plant-based (grain and vegetable) sources.[15][14] However, estimates have ranged from 1.4–5.7 mg per day, too.[16] The amount of strontium in a given food source varies by the amount of strontium in the soil, which may explain the variability in intake estimates.[15][14]

    What other forms of strontium are used in medicine?

    The radioactive forms of strontium (Sr-89 and Sr-90) are used clinically in stent implantation, brachytherapy, ocular therapies, and cancer treatment.[20][21][22][23][24][25][26][27][28][29] Radioactive strontium is not available outside of the clinic or hospital setting.

    Strontium ranelate is used in Europe by prescription (not over the counter) for treating osteoporosis. However, strontium ranelate is not currently approved in the US because of the risk of cardiovascular adverse events.[13]

    What are strontium’s main benefits?

    The currently available evidence does not demonstrate the benefits of strontium formulations that can be obtained for oral supplementation over the counter. Though clinical evidence is lacking, the available preclinical evidence suggests that strontium could improve bone strength (preventing bone loss and fractures related to bone loss).[16][15][14]

    When used as an additive to toothpaste or creams and applied topically, strontium has been shown clinically to reduce dental and skin sensitivities or irritation.[17][5][6][16][2][3][4]

    What effect might strontium have on bone or dental health?

    One case study on postmenopausal vertebral fracture found that taking 680 mg of strontium chloride daily for over two years increased bone mineral density in one person.[30] Otherwise, clinical evidence largely focuses on the use of strontium ranelate for bone health. In the US, strontium supplements are available for adults and children over the age of 4 and can range from 0.01–2,000 mg per day.[1]

    For hypersensitive teeth, pastes containing 2–10% strontium chloride or 8% strontium acetate (twice per day in normal brushing habits) have shown some success.[17][5][6][7][8][9][10][11][12] However, as an ingredient, it has largely been abandoned in dental sensitivity pastes and replaced by other desensitizers, so it may be difficult to find over the counter in some countries.

    What are strontium’s main drawbacks?

    Because of their similarities, strontium and calcium compete in the body. For example, strontium competes with calcium for absorption, notably in the intestines and renal tubules.[15] Calcium tends to be preferred physiologically, though, so taking the two minerals together may reduce the absorption and retention of strontium. Strontium absorption is reduced by phosphate and increased by vitamin D.[13] For these reasons, supplement labels will often recommend taking these supplements separately and also ensuring that adequate calcium is consumed.[1][14][15]

    As we age, how the body differentiates between strontium and calcium can vary. In early childhood, during bone development, excess exposure to strontium can impede bone growth and cause strontium-induced rickets. Though these risks are not as concerning for adults, strontium can still interfere with normal bone development when taken in circumstances where vitamin D, phosphorus, and calcium intakes are insufficient.[13][16]

    In observational evidence on hypertension in pregnancy, higher blood strontium levels were associated with hypertensive disorders, but a clear cause-and-effect relationship could not be determined.[18]

    How does strontium work?

    Bone strength is maintained through cycles of bone formation and resorption via specialized cells called osteoblasts (formation) and osteoclasts (resorption). When bone resorption starts to exceed bone formation, bone strength suffers, leading to conditions like osteoporosis.[19]

    When absorbed, almost all of the strontium ends up in bones, teeth, and joint structures.[16] Once incorporated into the bone, calcium and strontium appear to behave similarly.[15][14][16] Strontium may promote the new formation of bone by increasing the number of osteoblasts and preventing their destruction.[14][16]

    Though we still don’t have a complete understanding of how strontium works in the body, one possible mechanism may be that it works its way into bone cells to fill the gaps left by excessive resorption.[15][14] When used as a toothpaste additive, strontium is believed to work by blocking the exposed dentine tubules that produce dental hypersensitivity.[17][5][6]

    In some preclinical (animal) studies, strontium seems to reduce pro-inflammatory cytokines to reduce inflammation.[16] If the same anti-inflammatory activity occurs in humans, that could explain why it has shown some evidence of being useful for reducing skin irritation and itching as part of topical ointments.[2][3][4]

    Update History