Overview

SCIENTIFIC SCORE
Possibly Effective
Based on 31 Researches
7.5
USERS' SCORE
Moderately Good
Based on 7 Reviews
7.3
Supplement Facts
Serving Size: 2 Caplets
Serving Per Container:  100
Amount Per Serving
%DV
Total Sugars
0 g 
**
Includes 0 g Added Sugars 
0%*
Sugar Alcohols
0 g
**
Vitamin D
12.5 mcg (500 IU)
63%
Calcium
400 mg
31%
Sodium
5 mg
<1%

Top Medical Research Studies

We examined a collection of randomized controlled trials to determine the impact of calcium plus vitamin D supplementation on fracture prevention.

The results revealed a promising 15% reduction in total fractures and a remarkable 30% drop in hip fractures among those taking these supplements.

This convincing evidence supports the recommendation of calcium and vitamin D for reducing fracture risk, especially in older adults, whether living at home or in care facilities.
Read More
We aimed to understand how vitamin D influences bone health and helps combat osteoporosis, a condition that weakens bones. In our study, we used various mouse models, including those that mimic a deficiency in active vitamin D. Through a range of advanced methods, we assessed how changes in vitamin D levels affected bone structure and metabolism.

The research revealed that insufficient vitamin D led to a drop in Sirt1, a gene that plays a crucial role in maintaining bone density. This lack of Sirt1 resulted in increased bone loss. However, when we boosted Sirt1 levels in bone stem cells, we observed a reversal in bone loss. This improvement happened because higher Sirt1 levels reduced oxidative stress, slowed down aging processes in bone cells, and enhanced new bone formation while curbing bone resorption.

Additionally, our findings indicated that vitamin D directly stimulates Sirt1 expression in these stem cells, which is vital for bone health. We also explored the effects of resveratrol, a natural compound known for activating Sirt1, and found it helped alleviate osteoporosis symptoms linked to vitamin D deficiency by enhancing the relationship between Sirt1 and another protein called PGC1α, which supports bone formation and energy metabolism.

This research underscores the importance of the vitamin D-Sirt1/PGC1α axis in bone metabolism, providing insight into how vitamin D can serve as a target for osteoporosis prevention and treatment.
Read More
We explored the effects of vitamin D supplementation on osteoporosis, especially among individuals at risk for this condition. The Osteoporosis Research and Information Group (GRIO) highlighted the critical difference between daily and intermittent vitamin D dosing.

Current literature indicates that taking high doses of vitamin D intermittently, such as 60,000 IU a month, can actually elevate the chances of falls, fractures, and even premature death in some groups. Conversely, daily supplementation of 800-1000 IU, particularly alongside calcium, has been shown to reduce falls and non-vertebral fractures in the elderly who have a vitamin D deficiency.

Before anyone starts supplementing, it is crucial to measure their vitamin D levels to achieve a target concentration of 30 to 60 ng/mL. For those needing a quick boost in vitamin D levels—like patients showing symptoms of osteomalacia or those with critically low vitamin D—a starting loading dose followed by daily maintenance is the preferred approach. If daily options aren’t available, of course, a smaller intermittent dose can be a temporary solution until better options are accessible.
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Most Useful Reviews

7.5
Easily absorbed
9 people found this helpful
I trust Citrical for my osteoporosis management as I have been taking calcium supplements daily since my diagnosis two years ago. It absorbs easily, and I appreciate that I can take it with or without food. Although I expected the petites to be smaller, they assist well with swallowing.
Read More
7.5
Significant improvement noted
1 people found this helpful
Several years ago, my mother was diagnosed with osteoporosis. We tried numerous drugs, but none were effective until I found this one on iHerb. It truly works. Each year, she undergoes a bone density X-ray, which previously showed no improvement, only deterioration. After starting the calcium supplement, her indicators began to improve almost immediately. While results aren't instantaneous, she had a noticeable improvement after six months, which is fantastic! The supply lasts a long time. She also takes vitamin D.
Read More
4
Size concerns noted
3 people found this helpful
I rated this 4 stars as each serving only contains 400 mg. I have osteoporosis, so I take six daily compared to four of the larger tablets. I appreciate the smaller size which makes them easier to swallow, but six daily feels excessive.
Read More

Medical Researches

SCIENTIFIC SCORE
Possibly Effective
Based on 31 Researches
7.5
  • All Researches
We explored how the combination of calcium, vitamin D, and zinc impacts osteoporosis in ovariectomized rats. Using a well-structured study design, we divided 49 rats into various groups to compare results against a control.

Our findings suggest that this combined supplement helps enhance calcium absorption and reduces bone deterioration by lowering specific osteoporosis-related factors. This could point toward a potential alternative treatment for postmenopausal osteoporosis, though further research in humans is necessary.
Read More
We examined the effects of teriparatide combined with calcium and vitamin D versus standard calcium and vitamin D treatment on bone health in premenopausal women with pregnancy- and lactation-associated osteoporosis.

In our study, 19 women received teriparatide, while 8 only received calcium and vitamin D over 24 months. Results showed that those treated with teriparatide experienced significantly greater increases in bone mineral density at the lumbar spine after 12 and 24 months, indicating better bone health outcomes.

Overall, we found that teriparatide treatment substantially benefits women facing this rare condition.
Read More
We focused on the potential of nanoscale calcium salt formulations combined with vitamin D and natural minerals to treat osteoporosis. In our study, these innovative formulations showed promising results by enhancing bone density and reducing bone resorption in osteoporotic rats.

The tablets increased osteoblast activity and decreased osteoclast activity without causing toxicity. This dual action positions these calcium salt nanocomposites as a novel approach in osteoporosis management, offering a safer alternative to traditional treatments.
Read More
9
Calcium and vitamin D enhance treatment
We explored how adding vitamin D and calcium to denosumab therapy impacts bone health in patients with primary osteoporosis over four years.

The study involved two groups: one receiving just denosumab and another receiving denosumab with vitamin D and calcium.

Both groups saw improvements in bone health, but the combination group showed significant gains in hip bone density at 12 months and lumbar bone density from 24 to 48 months.

This suggests that ongoing vitamin D and calcium supplementation is beneficial alongside denosumab treatment.
Read More
We examined a collection of randomized controlled trials to determine the impact of calcium plus vitamin D supplementation on fracture prevention.

The results revealed a promising 15% reduction in total fractures and a remarkable 30% drop in hip fractures among those taking these supplements.

This convincing evidence supports the recommendation of calcium and vitamin D for reducing fracture risk, especially in older adults, whether living at home or in care facilities.
Read More

User Reviews

USERS' SCORE
Moderately Good
Based on 7 Reviews
7.3
  • All Reviews
  • Positive Reviews
  • Negative Reviews
7.5
Easily absorbed
9 people found this helpful
I trust Citrical for my osteoporosis management as I have been taking calcium supplements daily since my diagnosis two years ago. It absorbs easily, and I appreciate that I can take it with or without food. Although I expected the petites to be smaller, they assist well with swallowing.
Read More
7.5
Significant improvement noted
1 people found this helpful
Several years ago, my mother was diagnosed with osteoporosis. We tried numerous drugs, but none were effective until I found this one on iHerb. It truly works. Each year, she undergoes a bone density X-ray, which previously showed no improvement, only deterioration. After starting the calcium supplement, her indicators began to improve almost immediately. While results aren't instantaneous, she had a noticeable improvement after six months, which is fantastic! The supply lasts a long time. She also takes vitamin D.
Read More
4
Size concerns noted
3 people found this helpful
I rated this 4 stars as each serving only contains 400 mg. I have osteoporosis, so I take six daily compared to four of the larger tablets. I appreciate the smaller size which makes them easier to swallow, but six daily feels excessive.
Read More
7.5
Slowed progression noted
Pros: Smaller than standard calcium supplements, each dose contains a good 400 mg and is easy to swallow with no taste. It includes vitamin D, which helps the calcium go into bones instead of arteries. Cons: I need to take two tablets three times a day to meet my calcium needs, and I prefer capsules over tablets. I am 66, have osteopenia/osteoporosis, and taking these tablets has reportedly slowed the progression as per my dexascan.
Read More
6
Effective calcium dosage
The primary reason I chose this product was its calcium content combined with vitamin D. At my age, I need 1200 mg of calcium daily due to osteoporosis, and options with higher calcium content are scarce. I prefer taking one tablet in the morning and another in the afternoon to maximize vitamin D absorption without overdosing. I appreciate that the calcium is in citrate form, which is easier for the body to absorb. The price is competitive for the benefits provided.
Read More

Frequently Asked Questions

7.5
Significant improvement noted
1 people found this helpful
Several years ago, my mother was diagnosed with osteoporosis. We tried numerous drugs, but none were effective until I found this one on iHerb. It truly works. Each year, she undergoes a bone density X-ray, which previously showed no improvement, only deterioration. After starting the calcium supplement, her indicators began to improve almost immediately. While results aren't instantaneous, she had a noticeable improvement after six months, which is fantastic! The supply lasts a long time. She also takes vitamin D.
7.5
Slowed progression noted
Pros: Smaller than standard calcium supplements, each dose contains a good 400 mg and is easy to swallow with no taste. It includes vitamin D, which helps the calcium go into bones instead of arteries. Cons: I need to take two tablets three times a day to meet my calcium needs, and I prefer capsules over tablets. I am 66, have osteopenia/osteoporosis, and taking these tablets has reportedly slowed the progression as per my dexascan.
7
Prevention effective
Calcium tablets that I've consumed for many years have been effective in preventing osteoporosis, which is excellent!
6
Effective calcium dosage
The primary reason I chose this product was its calcium content combined with vitamin D. At my age, I need 1200 mg of calcium daily due to osteoporosis, and options with higher calcium content are scarce. I prefer taking one tablet in the morning and another in the afternoon to maximize vitamin D absorption without overdosing. I appreciate that the calcium is in citrate form, which is easier for the body to absorb. The price is competitive for the benefits provided.
We examined a collection of randomized controlled trials to determine the impact of calcium plus vitamin D supplementation on fracture prevention.

The results revealed a promising 15% reduction in total fractures and a remarkable 30% drop in hip fractures among those taking these supplements.

This convincing evidence supports the recommendation of calcium and vitamin D for reducing fracture risk, especially in older adults, whether living at home or in care facilities.
9
Calcium and vitamin D enhance treatment
We explored how adding vitamin D and calcium to denosumab therapy impacts bone health in patients with primary osteoporosis over four years.

The study involved two groups: one receiving just denosumab and another receiving denosumab with vitamin D and calcium.

Both groups saw improvements in bone health, but the combination group showed significant gains in hip bone density at 12 months and lumbar bone density from 24 to 48 months.

This suggests that ongoing vitamin D and calcium supplementation is beneficial alongside denosumab treatment.
We aimed to find out if calcium and vitamin D supplementation can improve bone mineral density (BMD) in healthy premenopausal women. After reviewing seven randomized controlled trials with nearly 1,000 participants, we found no significant improvements in total hip or lumbar spine BMD compared to placebo.

Our evidence indicates that neither calcium nor vitamin D—alone or combined—showed benefits for increasing bone strength or preventing fractures in this group. This suggests that there is little support for recommending these supplements to enhance bone health in healthy premenopausal women.
4
Vitamin D and osteoporosis treatment risks
We aimed to understand how vitamin D, when taken alongside calcium, affects individuals dealing with osteoporosis. This study involved 204 participants aged between 50 and 89 years, all receiving a specific daily dose of calcium carbonate and alfacalcidol for at least a year.

Our findings reveal an important aspect of this treatment: while calcium and vitamin D can be beneficial for bone health, there's a concerning association with kidney stone formation among users. Particularly, those with a history of recurrent kidney stones seemed to face an increased risk, which may be linked to higher urinary calcium excretion as a result of the supplements.

This highlights a dual-edged sword in osteoporosis treatment—while we seek to strengthen bones, we also have to consider potential harm. Thus, anyone considering or currently using these supplements should consult with their healthcare provider to carefully weigh the benefits against the risks, especially if they have a past of kidney stones.

References

  1. Liu S, Li J, Zhang M. Determination of immune factor levels in serum and local hematoma samples of osteoporotic fracture patients and clinical study of the effect of active vitamin D3 treatment on immune factor levels. J Orthop Surg Res. 2023;18:291. 10.1186/s13018-023-03777-7
  2. Wang S, Luo Z, Luo H, Li Z, Yuan Z, et al. Effects of a calcium/vitamin D/Zinc combination on anti-osteoporosis in ovariectomized rats. J Trace Elem Med Biol. 2023;77:127138. 10.1016/j.jtemb.2023.127138
  3. Méndez-Sánchez L, Clark P, Winzenberg TM, Tugwell P, Correa-Burrows P, et al. Calcium and vitamin D for increasing bone mineral density in premenopausal women. Cochrane Database Syst Rev. 2023;1:CD012664. 10.1002/14651858.CD012664.pub2
  4. Santos LAA, Lima TB, de Carvalho Nunes HR, Qi X, Romeiro FG. Two-year risedronate treatment for osteoporosis in patients with esophageal varices: a non-randomized clinical trial. Hepatol Int. 2022;16:1458. 10.1007/s12072-022-10366-z
  5. Lampropoulou-Adamidou K, Trovas G, Triantafyllopoulos IK, Yavropoulou MP, Anastasilakis AD, et al. Teriparatide Treatment in Patients with Pregnancy- and Lactation-Associated Osteoporosis. Calcif Tissue Int. 2021;109:554. 10.1007/s00223-021-00871-y
  6. Dashnyam K, Bayaraa O, Mandakhbayar N, Park JH, Lee JH, et al. Nanoscale Calcium Salt-Based Formulations As Potential Therapeutics for Osteoporosis. ACS Biomater Sci Eng. 2020;6:4604. 10.1021/acsbiomaterials.0c00219
  7. Li S, Xi C, Li L, Long Z, Zhang N, et al. Comparisons of different vitamin D supplementation for prevention of osteoporotic fractures: a Bayesian network meta-analysis and meta-regression of randomised controlled trials. Int J Food Sci Nutr. 2021;72:518. 10.1080/09637486.2020.1830264
  8. Suzuki T, Nakamura Y, Kato H. Vitamin D and Calcium Addition during Denosumab Therapy over a Period of Four Years Significantly Improves Lumbar Bone Mineral Density in Japanese Osteoporosis Patients. Nutrients. 2018;10. 10.3390/nu10030272
  9. García-Gomáriz C, Blasco JM, Macián-Romero C, Guillem-Hernández E, Igual-Camacho C. Effect of 2 years of endurance and high-impact training on preventing osteoporosis in postmenopausal women: randomized clinical trial. Menopause. 2018;25:301. 10.1097/GME.0000000000001005
  10. Nakamura Y, Suzuki T, Yoshida T, Yamazaki H, Kato H. Vitamin D and Calcium Are Required during Denosumab Treatment in Osteoporosis with Rheumatoid Arthritis. Nutrients. 2017;9. 10.3390/nu9050428
  11. Brech GC, Ciolac EG, Peterson MD, Greve JM. Serum 25-hydroxyvitamin D levels are associated with functional capacity but not with postural balance in osteoporotic postmenopausal women. Clinics (Sao Paulo). 2017;72:11. 10.6061/clinics/2017(01)03
  12. Florenzano P, Mezzano V, Le-Bert M, González G. [Bone involvement in systemic mastocytosis: Report of two cases]. Rev Med Chil. 2016;144:401. 10.4067/S0034-98872016000300018
  13. Safer U, Safer VB, Demir SO, Yanikoglu I. Effects of Bisphosphonates and Calcium plus Vitamin-D Supplements on Cognitive Function in Postmenopausal Osteoporosis§. Endocr Metab Immune Disord Drug Targets. 2016;16:56.
  14. Weaver CM, Alexander DD, Boushey CJ, Dawson-Hughes B, Lappe JM, et al. Calcium plus vitamin D supplementation and risk of fractures: an updated meta-analysis from the National Osteoporosis Foundation. Osteoporos Int. 2016;27:367. 10.1007/s00198-015-3386-5
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  16. Overton ET, Chan ES, Brown TT, Tebas P, McComsey GA, et al. Vitamin D and Calcium Attenuate Bone Loss With Antiretroviral Therapy Initiation: A Randomized Trial. Ann Intern Med. 2015;162:815. 10.7326/M14-1409
  17. Afonso ML, Capelas ML, Pimenta NM, Santos T, Mäkitie A, et al. A Systematic Review of Vitamin D Supplementation in Oncology: Chance of Science or Effectiveness?. Nutrients. 2025;17. 10.3390/nu17040634
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  19. Skubica P, Hoffmanova I, Dankova P. Chronically increased osteoclastogenesis in adult celiac disease patients does not hinder improvement in bone health induced by gluten-free diet: Role of vitamin D, OPG and IL-6. J Nutr Biochem. 2025. 10.1016/j.jnutbio.2025.109871
  20. Pickering ME, Souberbielle JC, Boutten A, Breuil V, Briot K, et al. Daily or intermittent vitamin D supplementation in patients with or at risk of osteoporosis: Position statement from the GRIO. Joint Bone Spine. 2025;92:105858. 10.1016/j.jbspin.2025.105858
  21. Shi L, Bao Y, Deng X, Xu X, Hu J. Association between calcium and vitamin D supplementation and increased risk of kidney stone formation in patients with osteoporosis in Southwest China: a cross-sectional study. BMJ Open. 2025;15:e092901. 10.1136/bmjopen-2024-092901
  22. Zhang SB, Yang J, Xu HW, Yi YY, Ren CX, et al. Association Between 25-hydroxyvitamin D Status and New Vertebral Fractures Post Percutaneous Vertebral Augmentation in Patients During Postmenopause: A Retrospective Case-control Study. Pain Physician. 2025;28:E31.
  23. Yang C, Chen L, Guo X, Sun H, Miao D. The Vitamin D-Sirt1/PGC1α Axis Regulates Bone Metabolism and Counteracts Osteoporosis. J Orthop Translat. 2025;50:211. 10.1016/j.jot.2024.10.011
  24. Kuwabara N, Kanda J, Sato S, Nakagawa S. Impact of Daily High Ergosterol Intake for 14 Weeks in Ovariectomized Rats on Cholesterol and Vitamin D Biosynthesis Pathways. Biol Pharm Bull. 2025;48:39. 10.1248/bpb.b24-00536
  25. McCarrison S, Abdelrahman S, Quinlivan R, Keen R, Wong SC. Pharmacological and non-pharmacological therapies for prevention and treatment of osteoporosis in Duchenne Muscular Dystrophy: A systematic review. Bone. 2025;193:117410. 10.1016/j.bone.2025.117410
  26. Ma M, Zhang Y, Liu J, Tian C, Duan Z, et al. Associations of the serum 25-hydroxyvitamin D with mortality among patients in osteopenia or osteoporosis. Bone. 2025. 10.1016/j.bone.2025.117408
  27. Wang JC, Chung SM, Wu PT, Tu YK, Lai PC, et al. Optimizing bone health in people living with HIV: insights from a network meta-analysis of randomized controlled trials. EClinicalMedicine. 2025;81:103103. 10.1016/j.eclinm.2025.103103
  28. Chen L, Lin S, He X, Ye J, Huang Y, et al. A calcium-loaded complex based on Antarctic krill protein and supplemented with pectin promotes calcium absorption and bone health. Int J Biol Macromol. 2025. 10.1016/j.ijbiomac.2025.141634
  29. Ma R, Romano E, Ashworth M, Vancampfort D, Solmi M, et al. Is there a disparity in osteoporosis referral and treatment among people with affective disorders? A ten-year data linkage study. Gen Hosp Psychiatry. 2025;94:56. 10.1016/j.genhosppsych.2025.02.009
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  31. Joris V, Balmayor ER, van Griensven M. miR-125b differentially impacts mineralization in dexamethasone and calcium-treated human mesenchymal stem cells. Mol Ther Nucleic Acids. 2025;36:102446. 10.1016/j.omtn.2024.102446
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