Supplement Facts
Serving Size: 1 Tablet
Amount Per Serving
%DV
Calcium (as Calcium Carbonate)
600 mg
46%
The product is found useful for the following medical conditions
Allergies details
SCIENTIFIC SCORE
No researches found
N/A
USERS' SCORE
Good
Based on 4 Reviews
8.6
9
Life-changing experience
Most Useful Review
90 people found this helpful
Excellent! I had severe issues with my immune system for two years, often being sick, and allergies seemed to emerge from nowhere, which left me utterly exhausted each day. It was quite challenging. However, once I started taking this vitamin, my life transformed completely! My doctors are astonished at the improvements I've made.
Updated: Mar 2026
Back Pain details
SCIENTIFIC SCORE
Likely Very Effective
Based on 1 Research
9
USERS' SCORE
Good
Based on 2 Reviews
8.5
9
We explored the impact of calcium and vitamin D supplementation combined with sling core stabilization training on back pain in a 70-year-old female patient suffering from osteoporosis. The patient engaged in this form of exercise three times a week, focusing on strengthening the deep muscles of her spine.
After a year of dedicated training, not only did her back pain significantly improve, but a follow-up examination also indicated an increase in her bone mineral density. This suggests that the combined approach of exercise and supplementation might promote better bone health and potentially reduce pain.
However, it’s important to note that while we saw positive changes in this case, the specific contributions of calcium alone cannot be clearly identified due to the concurrent treatments involved. Therefore, we recognize that further studies are needed to isolate calcium's effects to conclusively determine its role in managing back pain effectively.
After a year of dedicated training, not only did her back pain significantly improve, but a follow-up examination also indicated an increase in her bone mineral density. This suggests that the combined approach of exercise and supplementation might promote better bone health and potentially reduce pain.
However, it’s important to note that while we saw positive changes in this case, the specific contributions of calcium alone cannot be clearly identified due to the concurrent treatments involved. Therefore, we recognize that further studies are needed to isolate calcium's effects to conclusively determine its role in managing back pain effectively.
9
Pain relief noted
Most Useful Review
1 people found this helpful
Excellent calcium complex! I have found that this natural formulation is easily absorbed by my body. Since starting it, my back pain has improved, and I no longer experience discomfort related to weather changes after an old fracture. I'm very pleased with the results and will order more!
Updated: Mar 2026
Leg Cramps details
SCIENTIFIC SCORE
Questionable
Based on 8 Researches
5.9
USERS' SCORE
Good
Based on 3 Reviews
8.5
9
Calcium dobesilate reduces leg cramps
We examined the benefits of calcium dobesilate for patients suffering from chronic venous insufficiency (CVI), particularly focusing on how it impacts symptoms like leg cramps. In a systematic evaluation of ten different clinical trials involving 778 patients, we compared the effects of calcium dobesilate to a placebo.
Our analysis found that calcium dobesilate significantly reduced night cramps, helping patients nearly twice as much as those who received a placebo. The number needed to treat for this relief was calculated to be 8, indicating that for every eight patients treated with calcium dobesilate, one experienced noticeable improvement.
Moreover, patients also reported less discomfort, with a number needed to treat of 4 for that symptom. Interestingly, we noted that those with more severe symptoms experienced even greater relief, suggesting that calcium dobesilate is particularly effective for patients with advanced CVI. However, both doses tested—1,000 mg and 1,500 mg—proved equally effective, which is good news as it suggests that a lower dose might suffice.
Additionally, we found that adverse events were not significantly different from the placebo group, indicating a favorable safety profile. While calcium dobesilate shows promise, we acknowledge the need for further studies to solidify these findings and explore its efficacy in various CVI stages.
Our analysis found that calcium dobesilate significantly reduced night cramps, helping patients nearly twice as much as those who received a placebo. The number needed to treat for this relief was calculated to be 8, indicating that for every eight patients treated with calcium dobesilate, one experienced noticeable improvement.
Moreover, patients also reported less discomfort, with a number needed to treat of 4 for that symptom. Interestingly, we noted that those with more severe symptoms experienced even greater relief, suggesting that calcium dobesilate is particularly effective for patients with advanced CVI. However, both doses tested—1,000 mg and 1,500 mg—proved equally effective, which is good news as it suggests that a lower dose might suffice.
Additionally, we found that adverse events were not significantly different from the placebo group, indicating a favorable safety profile. While calcium dobesilate shows promise, we acknowledge the need for further studies to solidify these findings and explore its efficacy in various CVI stages.
9
Stable joints observed
Most Useful Review
I have been using 21st Century Calcium Supplement 600 for several weeks and I'm pleased with the results. Each tablet contains 600mg of calcium, essential for maintaining strong bones and teeth. I've found them easy to swallow without any stomach upset. Since starting this supplement, I’ve noticed my joints feel more stable and I’ve had no issues with muscle cramps, which are often linked to a lack of calcium.
Updated: Apr 2025
Pelvic Pain details
SCIENTIFIC SCORE
No researches found
N/A
USERS' SCORE
Good
Based on 2 Reviews
8.5
9
Knee health improved
Most Useful Review
My knees feel healthier, and I no longer experience pain when walking.
Updated: Mar 2026
Sleep Apnea details
SCIENTIFIC SCORE
No researches found
N/A
USERS' SCORE
Good
Based on 4 Reviews
8.4
9
Quick relaxation
Most Useful Review
I take calcium half an hour before bed. It promotes relaxation and helps me fall asleep quickly. The dosage is appropriate for the reasonable price.
Updated: Mar 2026
Bone Pain details
SCIENTIFIC SCORE
Moderately Effective
Based on 1 Research
8
USERS' SCORE
Good
Based on 30 Reviews
8.3
8
We explored the impact of calcium treatment on bone pain in patients who developed osteomalacia, a condition linked to intravenous iron infusions. Our focus was on a group of 13 patients diagnosed with this condition, who experienced low phosphate levels due to excess fibroblast growth factor 23 (iFGF23) after receiving ferric carboxymaltose (FCM) infusions.
After halting the FCM infusions, these patients were given supportive treatment, which included phosphate, calcium, and active Vitamin D supplementation. We observed improvements in biochemical markers, including increased phosphate levels and reduced pain scores. However, it’s important to note that while calcium was part of the treatment regimen, we could not isolate its specific effects on bone pain from the other supportive measures used.
Ultimately, our findings highlight the importance of monitoring phosphate levels in patients receiving FCM, and stopping these infusions effectively addresses phosphate wasting. Although supportive treatment showed improvements in pain and bone density, the direct impact of calcium on bone pain remains unclear given the combination of treatments involved.
After halting the FCM infusions, these patients were given supportive treatment, which included phosphate, calcium, and active Vitamin D supplementation. We observed improvements in biochemical markers, including increased phosphate levels and reduced pain scores. However, it’s important to note that while calcium was part of the treatment regimen, we could not isolate its specific effects on bone pain from the other supportive measures used.
Ultimately, our findings highlight the importance of monitoring phosphate levels in patients receiving FCM, and stopping these infusions effectively addresses phosphate wasting. Although supportive treatment showed improvements in pain and bone density, the direct impact of calcium on bone pain remains unclear given the combination of treatments involved.
9
Joint pain relief
Most Useful Review
100 people found this helpful
Thanks to this supplement, I've forgotten about bone pain and my bones no longer crunch.
Updated: Mar 2026
Osteoporosis details
SCIENTIFIC SCORE
Possibly Effective
Based on 6 Researches
7
USERS' SCORE
Moderately Good
Based on 26 Reviews
7.9
9
Our research explored the effects of a new calcium-loaded complex, made from Antarctic krill protein and enriched with pectin, on calcium absorption and bone health in mice with calcium deficiency. We created a model that simulated calcium deficiency, which is a significant concern as it can contribute to osteoporosis.
We observed that chronic calcium deprivation led to decreased calcium absorption and deterioration of bone structure. However, the P + Ca + HMP complex significantly improved calcium retention and increased the strength of the femur, indicating a positive impact on bone health.
Additionally, this complex improved the structure of the trabecular network, which is essential for maintaining strong bones. The presence of beneficial bacteria in the gut also rose after the intervention, and these were linked to better calcium absorption and bone synthesis. Overall, these findings point to the potential of the P + Ca + HMP complex as an effective calcium supplement that could help prevent calcium deficiency and thus support bone health.
We observed that chronic calcium deprivation led to decreased calcium absorption and deterioration of bone structure. However, the P + Ca + HMP complex significantly improved calcium retention and increased the strength of the femur, indicating a positive impact on bone health.
Additionally, this complex improved the structure of the trabecular network, which is essential for maintaining strong bones. The presence of beneficial bacteria in the gut also rose after the intervention, and these were linked to better calcium absorption and bone synthesis. Overall, these findings point to the potential of the P + Ca + HMP complex as an effective calcium supplement that could help prevent calcium deficiency and thus support bone health.
9
Value for osteoporosis
Most Useful Review
2 people found this helpful
21st Century Calcium Supplement 600 offers excellent value. As a sufferer of osteoporosis, taking calcium daily is essential, and buying a 400-tablet bottle at an affordable price is fantastic. It’s not in a gel cap, which suits me as a vegetarian.
Updated: Mar 2026
Blood Clot details
SCIENTIFIC SCORE
Moderately Effective
Based on 2 Researches
8.5
USERS' SCORE
Moderately Good
Based on 3 Reviews
7.8
8
We explored the impact of different calcium infusions on clotting risks in neonates undergoing cardiac surgery. Our study involved analyzing data from 135 babies who received either calcium chloride or calcium gluconate during their treatment.
The findings highlighted a significant concern: when using calcium chloride, the incidence of thrombotic events was notably higher compared to those treated with calcium gluconate. Specifically, the odds of experiencing a blood clot were over three times greater in patients given calcium chloride.
With an overall thrombus occurrence of 9.9%, we observed that only 4.6% of the group receiving calcium gluconate developed such complications compared to 15% in the calcium chloride group. The evidence suggests that switching from calcium chloride to calcium gluconate could potentially reduce the risk of harmful blood clots in these vulnerable patients.
The findings highlighted a significant concern: when using calcium chloride, the incidence of thrombotic events was notably higher compared to those treated with calcium gluconate. Specifically, the odds of experiencing a blood clot were over three times greater in patients given calcium chloride.
With an overall thrombus occurrence of 9.9%, we observed that only 4.6% of the group receiving calcium gluconate developed such complications compared to 15% in the calcium chloride group. The evidence suggests that switching from calcium chloride to calcium gluconate could potentially reduce the risk of harmful blood clots in these vulnerable patients.
6
Improves warmth and blood clot
Most Useful Review
Taking this supplement has made me feel better; it improves blood circulation and keeps me warm, which I appreciate. I also take it with vitamin D.
Updated: Mar 2026
Constipation details
SCIENTIFIC SCORE
Possibly Effective
Based on 2 Researches
7.5
USERS' SCORE
Moderately Good
Based on 6 Reviews
7.8
7
We explored how calcium intake relates to constipation, particularly focusing on individuals with metabolic syndrome, a condition that significantly impacts health. Using data from the National Health and Nutrition Examination Survey conducted between 2005 and 2010, we assessed the dietary habits of participants and looked at how often they experienced constipation.
Our findings suggest a noteworthy connection: as dietary calcium intake increases, the risk of constipation decreases among those with metabolic syndrome. This suggests that calcium could play a beneficial role in gastrointestinal health.
By analyzing dietary recalls and bowel movement frequency, we provided valuable insights into how making dietary changes can potentially improve symptoms for those affected by metabolic syndrome. This emphasizes the importance of dietary calcium as a simple yet impactful strategy for managing gastrointestinal issues in this specific population.
Our findings suggest a noteworthy connection: as dietary calcium intake increases, the risk of constipation decreases among those with metabolic syndrome. This suggests that calcium could play a beneficial role in gastrointestinal health.
By analyzing dietary recalls and bowel movement frequency, we provided valuable insights into how making dietary changes can potentially improve symptoms for those affected by metabolic syndrome. This emphasizes the importance of dietary calcium as a simple yet impactful strategy for managing gastrointestinal issues in this specific population.
9
No constipation noted
Most Useful Review
1 people found this helpful
I love this product! It’s a one-stop shop for my family’s needs, and I’m truly impressed with the quality and fast shipping. Since I started drinking this, my digestion has been excellent with no bloating or constipation. The packaging is superb, and the taste is great too.
Updated: Mar 2026
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