What is Strontium?
Strontium is a trace mineral that shares chemical similarities with calcium. It exists in several supplemental forms:
Strontium Citrate: The most common over-the-counter form available in dietary supplements, generally considered safe.
Strontium Ranelate: A pharmaceutical drug (brand name Protelos/Osseor) prescribed in some countries for osteoporosis. This form is NOT available as a dietary supplement.
Strontium Chloride/Carbonate: Less common supplement forms with varying bioavailability.
Strontium naturally occurs in soil, water, and food. About 99% of the body's strontium is stored in bones and teeth, where it incorporates into the bone matrix similarly to calcium.
Primary Functions & Benefits
Essential Functions:
Bone Formation: Stimulates osteoblast (bone-building cell) activity
Bone Resorption Reduction: Inhibits osteoclast (bone-breakdown cell) activity
Bone Matrix Integration: Incorporates into hydroxyapatite crystal structure
Calcium Metabolism: Influences calcium signaling pathways in bone cells
Health Benefits:
Increases bone mineral density (BMD) in clinical studies
Reduces vertebral and non-vertebral fracture risk
May reduce bone pain associated with osteoporosis
Supports bone healing and regeneration
Potentially beneficial for dental health
May help with osteoarthritis symptoms in some studies
Research Status:
Strontium ranelate has strong clinical evidence for osteoporosis treatment, but dietary strontium citrate has less robust research. The mechanism appears similar, but dosing and efficacy differ.
Recommended Daily Amounts
No Official RDA Established
Strontium is not classified as an essential nutrient, so there is no Recommended Dietary Allowance (RDA) or Adequate Intake (AI) established by nutritional authorities.
Typical Dietary Intake:
Average diet: 1-5 mg per day
Vegetarian diets: Often higher (more plant foods contain strontium)
Water: Varies widely by geographic location (0.1-30 mg/L)
Supplemental Doses Used in Research:
Bone health support: 340-680 mg elemental strontium daily
Strontium ranelate (prescription): 2,000 mg daily (equivalent to ~680 mg elemental strontium)
Common supplement protocols: 340-680 mg strontium citrate daily
Elemental Strontium Content:
Strontium citrate: ~30% elemental strontium
Strontium ranelate: ~34% elemental strontium
A 1,000 mg strontium citrate supplement provides approximately 300 mg elemental strontium
Food Sources
Natural Dietary Sources:
Seafood: Especially fish, shellfish, and seaweed
Whole grains: Wheat, oats, barley
Legumes: Beans, lentils, peas
Nuts and seeds: Brazil nuts, almonds
Leafy vegetables: Spinach, lettuce, cabbage
Root vegetables: Carrots, beets
Spices: Particularly those grown in strontium-rich soil
Drinking water: Variable content based on geology
High-Strontium Foods:
Seafood generally provides the highest dietary strontium
Plant foods grown in volcanic or limestone-rich soils tend to be higher
Strontium content varies significantly based on soil composition
Supplementation Guidelines
Typical Supplement Doses:
General bone support: 340-680 mg elemental strontium daily
Therapeutic use: Up to 680 mg elemental strontium (under supervision)
Most supplements: Provide 200-680 mg elemental strontium per serving
Timing & Administration:
Take at bedtime on an empty stomach for best absorption
Separate from calcium by at least 2 hours (they compete for absorption)
Separate from food by at least 2 hours
Consistent timing helps maintain steady bone incorporation
Duration:
Bone density improvements typically seen after 6-12 months
Long-term use (years) studied in clinical trials
Regular monitoring recommended with extended use
Synergistic Supplements
Take WITH Strontium (at different times):
Vitamin D3: Essential for calcium and strontium metabolism (take morning)
Vitamin K2 (MK-7): Directs calcium/minerals to bones (take morning)
Magnesium: Supports bone health and mineral balance (take morning/afternoon)
Boron: Enhances bone mineral retention
Vitamin C: Supports collagen formation in bone matrix
Beneficial But Separate Timing:
Calcium: Essential but take 2+ hours apart from strontium
Trace minerals: Zinc, copper, manganese for bone health
Collagen peptides: Support bone matrix structure
Complete Bone Health Protocol Example:
Morning: Calcium (500-600 mg), Vitamin D3 (2,000-4,000 IU), Vitamin K2 (100-200 mcg), Magnesium (200-400 mg)
Bedtime: Strontium citrate (680 mg elemental) on empty stomach
Interactions & What NOT to Take
Do NOT Take Simultaneously With:
Calcium supplements: Direct competition for absorption (separate by 2+ hours)
Dairy products: High calcium content blocks strontium absorption
Antacids: Containing calcium or aluminum
Calcium-fortified foods/drinks: Wait 2+ hours
Medications That May Interact:
Tetracycline antibiotics: Strontium may reduce antibiotic absorption
Quinolone antibiotics: Similar interaction as calcium
Bisphosphonates: Separate by several hours
Thyroid medications: May reduce absorption
Avoid Combining With:
High-dose calcium: Competes at absorption sites
Aluminum-containing products: May interfere with bone health
Excessive vitamin A: May impair bone health benefits
Who Should Take Strontium
Ideal Candidates:
Postmenopausal women with osteoporosis or osteopenia
Men with low bone mineral density
Individuals with family history of osteoporosis
People who cannot tolerate bisphosphonate medications
Those with history of fragility fractures
Individuals seeking natural bone support alternatives
People with inadequate response to calcium/vitamin D alone
May Benefit From Strontium:
Older adults with declining bone density
Those with malabsorption affecting calcium utilization
People recovering from bone fractures
Individuals with osteoarthritis (preliminary research)
Those with dental bone loss concerns
Who Should AVOID or Use Caution
Contraindications:
Severe kidney disease: Impaired strontium excretion (CrCl <30 mL/min)
History of blood clots: Strontium ranelate increases VTE risk (citrate form unclear)
Cardiovascular disease: Strontium ranelate has cardiac concerns (citrate less studied)
Children and adolescents: Safety not established
Pregnant or breastfeeding women: Crosses placenta and enters breast milk
Use Caution:
Mild to moderate kidney impairment
History of cardiovascular events
Those taking anticoagulants
People with hypocalcemia (correct first)
Individuals with vitamin D deficiency (correct first)
Strontium Ranelate Specific (Prescription):
Restricted use in Europe due to cardiovascular and VTE risks
Contraindicated with current/previous VTE
Only prescribed when other treatments unsuitable
Deficiency Symptoms
No Established Deficiency Syndrome
Strontium is not classified as an essential nutrient, so classical deficiency symptoms are not defined. However, inadequate strontium intake may theoretically affect:
Possible Effects of Low Strontium:
Suboptimal bone mineralization (theoretical)
Reduced bone density support (speculative)
Less protection against age-related bone loss
At-Risk for Low Intake:
People avoiding seafood and whole grains
Those with very restricted diets
Individuals in areas with low strontium in water/soil
Note on Deficiency:
Most researchers do not consider strontium deficiency a clinical concern, as dietary intake combined with bone remodeling appears adequate for normal function. Supplementation is viewed as therapeutic rather than correcting deficiency.
Toxicity Symptoms
Strontium Citrate Safety:
Generally well-tolerated at typical supplement doses (340-680 mg elemental daily). Toxicity rare with supplement use.
Potential Side Effects at High Doses:
Gastrointestinal upset (nausea, diarrhea, loose stools)
Bone pain or discomfort (rare)
Headache
Memory or cognitive issues (at very high doses)
Dermatitis or skin reactions (uncommon)
Strontium Ranelate Specific Risks (Prescription):
Increased risk of venous thromboembolism (blood clots)
Increased risk of myocardial infarction (heart attack)
DRESS syndrome (severe allergic reaction) - rare but serious
Gastrointestinal disturbances
Bone Scan Interference:
Strontium in bones increases bone density readings on DEXA scans more than actual bone strength increases. This creates artificially elevated BMD measurements (approximately 10% overestimation at 680 mg daily).
Long-Term Concerns:
Displaces calcium in bone (intentional but requires monitoring)
Kidney accumulation possible with impaired renal function
Radioactive strontium-90 contamination (environmental, not supplement)
Toxic Dose Levels:
No established upper tolerable limit for strontium citrate
Supplement doses of 340-680 mg elemental appear safe long-term
Doses above 1,000 mg elemental daily not recommended without supervision
Special Considerations
Bone Density Testing:
Inform healthcare providers about strontium use before DEXA scans
Strontium inflates BMD readings by approximately 10%
Some facilities can adjust calculations to account for strontium
Consider stopping strontium 2-4 weeks before baseline DEXA scan
Kidney Function:
Strontium is primarily excreted by kidneys (70% renal, 30% fecal)
Reduced kidney function increases strontium retention
Regular kidney function monitoring recommended for long-term use
Avoid if CrCl <30 mL/min
Cardiovascular Considerations:
Strontium ranelate has documented CV risks
Strontium citrate cardiovascular safety less studied
Those with heart disease should consult physician before use
Monitor for any unusual symptoms
Duration of Use:
Clinical studies have examined use for 3-5 years
Bone incorporation is cumulative over time
Some practitioners recommend periodic breaks (e.g., 1 month off per year)
Long-term safety beyond 5 years less studied
Quality & Purity:
Choose reputable brands with third-party testing
Avoid products contaminated with lead or other metals
Verify elemental strontium content on label
Pharmaceutical-grade strontium citrate preferred
Mechanism of Action
How Strontium Works in Bone:
Dual Action on Bone Cells:
Stimulates osteoblast differentiation and activity (builds bone)
Inhibits osteoclast differentiation and activity (reduces bone breakdown)
Bone Integration:
Strontium substitutes for calcium in hydroxyapatite crystals
Creates larger crystal structure (increases bone volume)
May not increase bone strength proportionally to density
Incorporated strontium is heavier than calcium (inflates DEXA readings)
Cellular Signaling:
Activates calcium-sensing receptors in bone cells
Influences RANKL/OPG pathway (regulates bone remodeling)
Affects Wnt signaling (promotes bone formation)
Strontium Citrate vs. Strontium Ranelate
Strontium Citrate (Supplement):
Available over-the-counter
Generally regarded as safe at typical doses
Less clinical evidence than ranelate
No prescription required
Fewer reported side effects
Lower regulatory scrutiny
Strontium Ranelate (Prescription):
Pharmaceutical drug with extensive clinical trials
Proven fracture reduction in large studies
Significant cardiovascular and VTE risks
Restricted or withdrawn in many countries
Requires physician monitoring
Not available as supplement
Efficacy Comparison:
Ranelate has stronger evidence base
Citrate mechanism appears similar
Citrate may require longer treatment duration
Individual response varies
Summary & Key Takeaways
Strontium is a trace mineral that supports bone health by stimulating bone formation and reducing bone breakdown. While not an essential nutrient, supplementation with strontium citrate may benefit those with osteoporosis or low bone density, particularly when other treatments are not suitable.
Critical Points:
Take on empty stomach at bedtime, separate from calcium by 2+ hours
Typical dose is 340-680 mg elemental strontium daily
Inflates DEXA scan readings by approximately 10%
Generally safe but avoid with severe kidney disease or cardiovascular conditions
Requires months of consistent use to see benefits
Should be part of comprehensive bone health protocol with calcium, vitamin D, K2, and magnesium
Bottom Line: Strontium citrate offers a natural approach to bone health support with relatively low risk at appropriate doses, but it should be used as part of a complete bone health strategy under healthcare supervision, especially for those with pre-existing medical conditions.
Would you like me to elaborate on any specific aspect of strontium supplementation or its use for particular conditions?