Overview

SCIENTIFIC SCORE
Possibly Effective
Based on 11 Researches
7.7
USERS' SCORE
Good
Based on 6 Reviews
8.7
Supplement Facts
Serving Size: 4 Tablets
Amount Per Serving
%DV
Calories
10
Total Carbohydrate
1 g
<1%**
Dietary Fiber
1 g
4%**
Vitamin D (as cholecalciferol)
15 mcg (600 IU)
75%
Calcium (as calcium citrate)
1000 mg
77%
Sodium†
20 mg
<1%

Top Medical Research Studies

9
Vitamin D counteracts blood clotting
Our research focused on understanding how Vitamin D (VitD) might influence blood clotting, especially in the context of COVID-19. We found that when human endothelial cells were exposed to IL-6—an inflammatory cytokine associated with severe COVID-19—it led to dysfunction in these cells. This dysfunction was marked by increased levels of Tissue Factor (TF) and cell adhesion molecules (CAMs), which promote blood clotting.

Remarkably, when we treated these endothelial cells with VitD, we observed a reversal of these harmful effects. VitD appeared to inhibit the expression of TF and CAMs and even modulated the levels of the ACE2 receptor, which is crucial for the entry of the virus into cells. Our findings suggest that VitD could play a protective role against the blood clotting complications associated with COVID-19 by counteracting IL-6's effects on endothelial cells.

Overall, this study paves the way for further research into VitD as a potential therapeutic option for mitigating thrombotic risks in COVID-19 patients.
Read More
8
We sought to understand how vitamin D levels might impact thrombus burden—essentially the amount of blood clotting—specifically in patients suffering from ST-elevation myocardial infarction (STEMI) who are about to undergo primary percutaneous coronary intervention (PCI), a common procedure to restore blood flow to the heart.

Our research involved 257 STEMI patients who were observed in a hospital setting over a year. We divided these patients into two groups: those with high thrombus burden and those with low thrombus burden. After looking at various factors, one clear finding emerged: patients with high thrombus burden had significantly lower vitamin D levels compared to those with low thrombus burden. In fact, the average vitamin D levels in patients with high thrombus burden were only 8.0 ng/mL compared to 17.9 ng/mL in those with low thrombus burden.

We also discovered that patients with high thrombus burden and low vitamin D levels had poorer outcomes post-PCI, including decreased blood flow and lower heart performance. Through further analysis, we found vitamin D levels were an independent predictor of thrombus burden. Those with levels above 17.6 ng/mL showed an impressive 81.8% sensitivity for predicting low thrombus burden.

Overall, our study indicates that maintaining adequate vitamin D levels could play a significant role in reducing the risks associated with blood clotting in heart attack patients undergoing critical interventions.
Read More
We set out to examine how vitamin D influences blood clot formation in prostate cancer patients. Participants in our study were divided into three groups: metastatic, non-metastatic, and a reference group. We treated their whole blood samples with a specific dose of Calcitriol, a form of vitamin D, to see how it affected clotting dynamics and the structure of blood components.

Our findings from tests like Thromboelastography revealed that while the non-metastatic group showed no major differences before and after treatment, the metastatic group exhibited a concerning hypercoagulable state. Interestingly, after vitamin D supplementation, the viscoelastic properties of the non-metastatic group improved significantly, aligning more closely with those of the healthier reference group.

Overall, our study suggests that vitamin D may create a more favorable environment for blood clotting, potentially leading to less dangerous clots in certain prostate cancer patients. This could be an important consideration for individuals at risk of thromboembolic events associated with their condition.
Read More

Most Useful Reviews

10
Calcium levels restored
11 people found this helpful
My mother, with her thyroid gland removed, relies on calcium supplementation and has struggled to maintain proper calcium levels until she tried this calcium citrate. Previous alternatives did not yield the desired blood test results. This product has successfully normalised her calcium levels, much to our delight! Despite the large pill size, it's the effectiveness in maintaining calcium that matters most.
Read More
9
Sensitive enamel improved
3 people found this helpful
This calcium supplement from a trusted brand is consistently effective for me. It has alleviated my sensitive tooth enamel, which now no longer reacts to heat and cold as it used to. The calcium citrate is well absorbed in the body, without depositing in blood vessels, unlike calcium carbonate. It includes 600ME of vitamin D, which also supports calcium absorption and is thought to be a beneficial supplement for immunity.
Read More
9
Good blood counts achieved
1 people found this helpful
I appreciate this medication for its calcium and vitamin D3 content, which enhances calcium absorption. The citrate form allows up to 70% absorption, unlike other forms that offer only about 30%. It does not irritate the stomach, making it safe for those with gastrointestinal issues. Following the treatment, I achieved good blood counts, and my calcium levels are now normal.
Read More

Medical Researches

SCIENTIFIC SCORE
Possibly Effective
Based on 11 Researches
7.7
  • All Researches
9
Vitamin D counteracts blood clotting
Our research focused on understanding how Vitamin D (VitD) might influence blood clotting, especially in the context of COVID-19. We found that when human endothelial cells were exposed to IL-6—an inflammatory cytokine associated with severe COVID-19—it led to dysfunction in these cells. This dysfunction was marked by increased levels of Tissue Factor (TF) and cell adhesion molecules (CAMs), which promote blood clotting.

Remarkably, when we treated these endothelial cells with VitD, we observed a reversal of these harmful effects. VitD appeared to inhibit the expression of TF and CAMs and even modulated the levels of the ACE2 receptor, which is crucial for the entry of the virus into cells. Our findings suggest that VitD could play a protective role against the blood clotting complications associated with COVID-19 by counteracting IL-6's effects on endothelial cells.

Overall, this study paves the way for further research into VitD as a potential therapeutic option for mitigating thrombotic risks in COVID-19 patients.
Read More
We explored the role of calcium in promoting blood coagulation using a new zeolite-embedded regenerated cellulose aerogel (Z-RCA). This innovative hemostatic agent was designed to minimize common issues seen with previous zeolite-based products, like heat-induced tissue damage and unwanted blood clotting elsewhere in the body.

Our results showed that this aerogel effectively absorbed blood while releasing calcium ions, which play a crucial role in the blood clotting process. By combining the properties of zeolite and the calcium-releasing ability of the aerogel, we found that Z-RCA not only facilitated quicker blood clotting but did so safely, with less risk of adverse effects.

In animal trials, we observed that Z-RCA stopped bleeding faster than existing options like Quikclot and notably reduced blood loss by over 62%. This combination of effectiveness and safety makes Z-RCA a promising solution for achieving efficient hemostasis during emergencies.
Read More
8
Vitamin D linked to clot risk
We set out to understand how levels of vitamin D, specifically serum 25-hydroxyvitamin D (25OHD), influence the risk of developing venous thromboembolism (VTE), which includes serious conditions like deep vein thrombosis and pulmonary embolism. To do this, we examined a large cohort of nearly 378,000 participants, all free from VTE at the start of the study.

Our analysis focused on the relationship between vitamin D levels and VTE risk, particularly in individuals with diabetes compared to those without. Over a median follow-up period of 12.5 years, we recorded just over 10,600 new cases of VTE.

The findings were quite revealing: higher serum 25OHD concentrations were associated with a lower risk of VTE. This inverse relationship was especially pronounced in participants with diabetes. Interestingly, while we assessed various genetic factors that could influence VTE risk, they did not significantly change how vitamin D affected the likelihood of developing a blood clot.

However, we did find that specific genetic variations in the vitamin D receptor appeared to enhance the protective effects of vitamin D against VTE. Overall, we are encouraged by our findings, which suggest that maintaining sufficient levels of vitamin D may help reduce the risk of blood clots, particularly in those already managing diabetes.
Read More
8
Vitamin D mitigates platelet aggregation
We explored how 1,25-Dihydroxyvitamin D3, a form of vitamin D, can influence platelet aggregation, particularly in the context of COVID-19. Platelet hyperreactivity is a condition where platelets are overly reactive, contributing to blood clotting issues often seen in COVID-19 patients. Our investigation focused on how vitamin D might help mitigate these issues by examining its direct effects in the laboratory.

We found that vitamin D significantly reduced platelet aggregation, especially when this aggregation was heightened by the SARS-CoV-2 spike protein. This effect appears to be linked to vitamin D's ability to inhibit certain signaling pathways involved in platelet activation. Notably, the treatment reduced the activation of integrin αIIbβ3, which plays a key role in platelet spreading and clumping.

By utilizing a particular Src family kinase inhibitor, we confirmed that there are overlapping pathways being influenced, as both vitamin D and the inhibitor showed similar effects in lowering platelet responses. Our findings suggest that vitamin D could serve as a beneficial treatment to help manage clotting in COVID-19, though further exploration is necessary.
Read More
8
We sought to understand how vitamin D levels might impact thrombus burden—essentially the amount of blood clotting—specifically in patients suffering from ST-elevation myocardial infarction (STEMI) who are about to undergo primary percutaneous coronary intervention (PCI), a common procedure to restore blood flow to the heart.

Our research involved 257 STEMI patients who were observed in a hospital setting over a year. We divided these patients into two groups: those with high thrombus burden and those with low thrombus burden. After looking at various factors, one clear finding emerged: patients with high thrombus burden had significantly lower vitamin D levels compared to those with low thrombus burden. In fact, the average vitamin D levels in patients with high thrombus burden were only 8.0 ng/mL compared to 17.9 ng/mL in those with low thrombus burden.

We also discovered that patients with high thrombus burden and low vitamin D levels had poorer outcomes post-PCI, including decreased blood flow and lower heart performance. Through further analysis, we found vitamin D levels were an independent predictor of thrombus burden. Those with levels above 17.6 ng/mL showed an impressive 81.8% sensitivity for predicting low thrombus burden.

Overall, our study indicates that maintaining adequate vitamin D levels could play a significant role in reducing the risks associated with blood clotting in heart attack patients undergoing critical interventions.
Read More

User Reviews

USERS' SCORE
Good
Based on 6 Reviews
8.7
  • All Reviews
  • Positive Reviews
  • Negative Reviews
10
Calcium levels restored
11 people found this helpful
My mother, with her thyroid gland removed, relies on calcium supplementation and has struggled to maintain proper calcium levels until she tried this calcium citrate. Previous alternatives did not yield the desired blood test results. This product has successfully normalised her calcium levels, much to our delight! Despite the large pill size, it's the effectiveness in maintaining calcium that matters most.
Read More
9
Sensitive enamel improved
3 people found this helpful
This calcium supplement from a trusted brand is consistently effective for me. It has alleviated my sensitive tooth enamel, which now no longer reacts to heat and cold as it used to. The calcium citrate is well absorbed in the body, without depositing in blood vessels, unlike calcium carbonate. It includes 600ME of vitamin D, which also supports calcium absorption and is thought to be a beneficial supplement for immunity.
Read More
9
Good blood counts achieved
1 people found this helpful
I appreciate this medication for its calcium and vitamin D3 content, which enhances calcium absorption. The citrate form allows up to 70% absorption, unlike other forms that offer only about 30%. It does not irritate the stomach, making it safe for those with gastrointestinal issues. Following the treatment, I achieved good blood counts, and my calcium levels are now normal.
Read More
9
Improved calcium levels
I have used this Solgar product for many years. Taking one tablet, which should be consumed before bedtime, has significantly improved my blood calcium levels.
Read More
7.5
Calcium absorption improved
This is my second order for calcium from this source. I am pleased with the results; muscle pain has ceased, and my blood calcium levels have improved following thyroid removal. After taking calcium citrate, my levels normalised. I also ordered vitamin D3, which is now at a healthy level. The rapid delivery was a pleasant surprise. Overall, I am very satisfied!
Read More

Frequently Asked Questions

10
Calcium levels restored
11 people found this helpful
My mother, with her thyroid gland removed, relies on calcium supplementation and has struggled to maintain proper calcium levels until she tried this calcium citrate. Previous alternatives did not yield the desired blood test results. This product has successfully normalised her calcium levels, much to our delight! Despite the large pill size, it's the effectiveness in maintaining calcium that matters most.
7.5
Blood tests improved
I purchased this for my grandmother, who suffers from calcium deficiency. After a short duration of use, she is already observing positive changes in her blood test results.
9
Good blood counts achieved
1 people found this helpful
I appreciate this medication for its calcium and vitamin D3 content, which enhances calcium absorption. The citrate form allows up to 70% absorption, unlike other forms that offer only about 30%. It does not irritate the stomach, making it safe for those with gastrointestinal issues. Following the treatment, I achieved good blood counts, and my calcium levels are now normal.
7.5
Calcium absorption improved
This is my second order for calcium from this source. I am pleased with the results; muscle pain has ceased, and my blood calcium levels have improved following thyroid removal. After taking calcium citrate, my levels normalised. I also ordered vitamin D3, which is now at a healthy level. The rapid delivery was a pleasant surprise. Overall, I am very satisfied!
9
Sensitive enamel improved
3 people found this helpful
This calcium supplement from a trusted brand is consistently effective for me. It has alleviated my sensitive tooth enamel, which now no longer reacts to heat and cold as it used to. The calcium citrate is well absorbed in the body, without depositing in blood vessels, unlike calcium carbonate. It includes 600ME of vitamin D, which also supports calcium absorption and is thought to be a beneficial supplement for immunity.
9
Improved calcium levels
I have used this Solgar product for many years. Taking one tablet, which should be consumed before bedtime, has significantly improved my blood calcium levels.
8
Vitamin D linked to clot risk
We set out to understand how levels of vitamin D, specifically serum 25-hydroxyvitamin D (25OHD), influence the risk of developing venous thromboembolism (VTE), which includes serious conditions like deep vein thrombosis and pulmonary embolism. To do this, we examined a large cohort of nearly 378,000 participants, all free from VTE at the start of the study.

Our analysis focused on the relationship between vitamin D levels and VTE risk, particularly in individuals with diabetes compared to those without. Over a median follow-up period of 12.5 years, we recorded just over 10,600 new cases of VTE.

The findings were quite revealing: higher serum 25OHD concentrations were associated with a lower risk of VTE. This inverse relationship was especially pronounced in participants with diabetes. Interestingly, while we assessed various genetic factors that could influence VTE risk, they did not significantly change how vitamin D affected the likelihood of developing a blood clot.

However, we did find that specific genetic variations in the vitamin D receptor appeared to enhance the protective effects of vitamin D against VTE. Overall, we are encouraged by our findings, which suggest that maintaining sufficient levels of vitamin D may help reduce the risk of blood clots, particularly in those already managing diabetes.
8
We sought to understand how vitamin D levels might impact thrombus burden—essentially the amount of blood clotting—specifically in patients suffering from ST-elevation myocardial infarction (STEMI) who are about to undergo primary percutaneous coronary intervention (PCI), a common procedure to restore blood flow to the heart.

Our research involved 257 STEMI patients who were observed in a hospital setting over a year. We divided these patients into two groups: those with high thrombus burden and those with low thrombus burden. After looking at various factors, one clear finding emerged: patients with high thrombus burden had significantly lower vitamin D levels compared to those with low thrombus burden. In fact, the average vitamin D levels in patients with high thrombus burden were only 8.0 ng/mL compared to 17.9 ng/mL in those with low thrombus burden.

We also discovered that patients with high thrombus burden and low vitamin D levels had poorer outcomes post-PCI, including decreased blood flow and lower heart performance. Through further analysis, we found vitamin D levels were an independent predictor of thrombus burden. Those with levels above 17.6 ng/mL showed an impressive 81.8% sensitivity for predicting low thrombus burden.

Overall, our study indicates that maintaining adequate vitamin D levels could play a significant role in reducing the risks associated with blood clotting in heart attack patients undergoing critical interventions.
We aimed to explore the relationship between vitamin D levels and anti-PF4 antibodies in individuals with mild COVID-19. Conducting our study at two hospitals in Jakarta with 160 patients, we discovered a significant negative correlation. Essentially, as serum levels of vitamin D—specifically measured as 25-hydroxy-cholecalciferol—decreased, we observed that anti-PF4 antibody levels increased among these patients.

Interestingly, our findings showed that the average vitamin D level was notably low at 15.1 ng/mL. Considering the recommended minimum levels above 30 ng/mL, it seems that maintaining adequate vitamin D levels could be beneficial. This could potentially help in managing inflammatory responses and thrombosis, which are prevalent in COVID-19 cases.

Furthermore, we noted that levels of P-selectin, a marker related to platelet activation, were significantly higher in moderate COVID-19 patients compared to those severely affected. These insights suggest that monitoring and optimizing vitamin D levels may play a crucial role in mitigating clotting risks among COVID-19 patients, particularly those with milder symptoms.
8
Vitamin D mitigates platelet aggregation
We explored how 1,25-Dihydroxyvitamin D3, a form of vitamin D, can influence platelet aggregation, particularly in the context of COVID-19. Platelet hyperreactivity is a condition where platelets are overly reactive, contributing to blood clotting issues often seen in COVID-19 patients. Our investigation focused on how vitamin D might help mitigate these issues by examining its direct effects in the laboratory.

We found that vitamin D significantly reduced platelet aggregation, especially when this aggregation was heightened by the SARS-CoV-2 spike protein. This effect appears to be linked to vitamin D's ability to inhibit certain signaling pathways involved in platelet activation. Notably, the treatment reduced the activation of integrin αIIbβ3, which plays a key role in platelet spreading and clumping.

By utilizing a particular Src family kinase inhibitor, we confirmed that there are overlapping pathways being influenced, as both vitamin D and the inhibitor showed similar effects in lowering platelet responses. Our findings suggest that vitamin D could serve as a beneficial treatment to help manage clotting in COVID-19, though further exploration is necessary.
We aimed to understand how vitamin D affects blood clotting, especially during pregnancy when women are already at a higher risk for blood clots. In a cross-sectional study, we compared the hemostatic profiles of two groups of pregnant women. One group had vitamin D deficiency, defined as levels below 50 nmol/L, while the other had adequate levels, at or above 100 nmol/L.

Our findings revealed that women with vitamin D deficiency exhibited increased levels of a protein called plasminogen activator inhibitor 1 (PAI-1). This protein is linked to blood clotting, and we saw that not only were the levels elevated, but the ratio of PAI-1 to another important protein, plasminogen activator inhibitor 2 (PAI-2), was also higher in the vitamin D deficient group.

This elevated ratio can indicate a greater risk of thrombotic events and is associated with complications during pregnancy. Consequently, we concluded that vitamin D deficiency poses a potential risk for increased thrombotic complications in pregnant women, underscoring the need for more research on the optimal vitamin D supplementation during pregnancy.

References

  1. Xiang H, Zhou C, Gan X, Huang Y, He P, et al. Relationship of Serum 25-Hydroxyvitamin D Concentrations, Diabetes, Vitamin D Receptor Gene Polymorphisms and Incident Venous Thromboembolism. Diabetes Metab Res Rev. 2025;41:e70014. doi:10.1002/dmrr.70014
  2. Rachman A, Iriani A, Irawan A, Juanputra S, Betsy R. Adequate serum 25-hydroxy-vitamin D levels are correlated with low anti-PF4 levels in mild COVID-19 Patients: An observational study. Medicine (Baltimore). 2024;103:e39252. doi:10.1097/MD.0000000000039252
  3. Wang R, Tian Z, Wang C, Zhang B, Zhu M, et al. 1,25-Dihydroxyvitamin D3 attenuates platelet aggregation potentiated by SARS-CoV-2 spike protein via inhibiting integrin αIIbβ3 outside-in signaling. Cell Biochem Funct. 2024;42:e4039. doi:10.1002/cbf.4039
  4. Andersen MK, Rüdiger IH, Vestergaard AL, Palarasah Y, Bor P, et al. Vitamin D Deficiency is Associated With Increased Plasminogen Activator Inhibitor 1/Plasminogen Activator Inhibitor 2 Ratio in Pregnancy. Clin Appl Thromb Hemost. 2023;29:10760296231201855. doi:10.1177/10760296231201855
  5. Şaylık F, Selçuk M, Akbulut T, Çınar T. The Association between Vitamin D Levels and Thrombus Burden in Patients with ST-Elevation Myocardial Infarction. J Tehran Heart Cent. 2022;17:48. doi:10.18502/jthc.v17i2.9835
  6. Uguz B, Oztas S, Zengin I, Topal D, Tiryakioglu SK, et al. Relationship between vitamin D deficiency and thrombus load in patients with ST-elevation myocardial infarction. Eur Rev Med Pharmacol Sci. 2022;26:7015. doi:10.26355/eurrev_202210_29885
  7. Hajimoradi B, Hosseini B, Alirezaei T, Pourmotahari F. 25-Hydroxy vitamin D level is associated with mean platelet volume in patients with acute coronary syndrome. Cardiovasc Hematol Disord Drug Targets. 2022. doi:10.2174/1871529X22666220418111905
  8. Hoek M, Schultz M, Alummoottil S, Aneck-Hahn N, Mathabe K, et al. Ex vivo Vitamin D supplementation improves viscoelastic profiles in prostate cancer patients. Clin Hemorheol Microcirc. 2022;81:221. doi:10.3233/CH-211353
  9. Cimmino G, Conte S, Morello M, Pellegrino G, Marra L, et al. Vitamin D Inhibits IL-6 Pro-Atherothrombotic Effects in Human Endothelial Cells: A Potential Mechanism for Protection against COVID-19 Infection?. J Cardiovasc Dev Dis. 2022;9. doi:10.3390/jcdd9010027
  10. Jin Z, Chen L, Liu X, Xia R, Li W, et al. Zeolite firmly anchored regenerated cellulose aerogel for efficient and biosafe hemostasis. Int J Biol Macromol. 2025;304:140743. doi:10.1016/j.ijbiomac.2025.140743
  11. Tran VA, Griffin EM, Elliott JD, Scholl RL, Hill RB, et al. Thrombotic Complications Associated With Right Atrial Lines in Neonates and Infants Undergoing Cardiac Surgery. Is Calcium Chloride a Culprit?. J Cardiothorac Vasc Anesth. 2025. doi:10.1053/j.jvca.2025.01.008
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