Overview

SCIENTIFIC SCORE
Possibly Effective
Based on 16 Researches
7.5
USERS' SCORE
Good
Based on 32 Reviews
8
Supplement Facts
Serving Size: 1 Capsule
Amount Per Serving
%DV
Vitamin D3 (as cholecalciferol)
125 mcg
625%
Vitamin K activity from:Vitamin K1 (as phytonadione)Vitamin K2 (as menaquinone-4)Vitamin K2 (as trans menaquinone-7)
2,100 mcg1,000 mcg1,000 mcg100 mcg
1,750%
Iodine [from Sea-Iodine™ Complex Blend (organic kelp and bladderwrack extracts, potassium iodide)]
1,000 mcg
667%

Top Medical Research Studies

9
Vitamin D3 modulates autoimmune response
We explored how Vitamin D3 impacts autoimmune thyroiditis, a specific autoimmune disorder. In this study, researchers established a mouse model of experimental autoimmune thyroiditis (EAT) to see how Vitamin D3 could influence this condition. After eight weeks of treatment, they assessed thyroid health and immune response through various methods, including staining tissues and measuring hormone levels.

Our observations revealed that administering Vitamin D3 helped reduce damage to the thyroid and decreased the presence of inflammatory cells within the thyroid. This treatment also led to lower levels of thyroid hormones and autoimmune antibodies in the blood, highlighting its positive effect on thyroid function. Additionally, Vitamin D3 appeared to promote the regulatory T cell (Treg) subset while decreasing the levels of Th17 cells, which are often involved in autoimmune processes.

Mechanistically, the study found that Vitamin D3 triggered specific pathways that influence Treg cell activity and survival. Notably, it activated a signaling pathway involving YAP and JAK/STAT, which are crucial for immune cell regulation. These findings suggest that Vitamin D3 could play a significant role in balancing immune responses in autoimmune thyroiditis, making it a promising candidate for further research and potential treatment strategies.
Read More
9
Vitamin D3 mitigates autoimmune thyroiditis
Our research aimed to understand how vitamin D3 affects autoimmune thyroiditis, particularly in the context of Hashimoto's thyroiditis, which is characterized by low levels of vitamin D3 in patients. We induced a model of autoimmune thyroiditis in female mice and treated them with vitamin D3 to see if it could alleviate the symptoms of this condition.

After 8 weeks of treatment, we observed that vitamin D3 significantly improved the condition of the thyroid in these mice. The inflammation that commonly accompanies autoimmune thyroiditis decreased, and levels of thyroid autoantibodies, which indicate the severity of the disorder, also dropped. Notably, the application of vitamin D3 inhibited the activity of harmful immune cells while promoting the function of protective cells, providing a better balance in the immune response.

Overall, our findings suggest that vitamin D3 supplementation could be a promising strategy to manage autoimmune thyroiditis by restoring immune balance and reducing inflammation. This not only enhances our understanding of the disease but also opens up potential avenues for treatment in humans facing similar issues with autoimmune disorders.
Read More
We aimed to understand how vitamin D3, specifically its active form 1,25(OH)D, affects autoimmune hepatitis (AIH), a complex autoimmune disease that causes liver damage. Researchers focused on the role of a special type of immune cell known as dendritic cells (DCs), which are influenced by vitamin D3 to promote a more balanced immune response.

Through our investigation using a mouse model, we observed that injecting these vitamin D3-modulated dendritic cells, which overexpress a molecule called PD-L1, significantly lessened liver injury and severity of autoimmune hepatitis. This treatment appeared to correct the imbalance between two types of T cells: regulatory T cells (TFR) and follicular helper T cells (TFH).

By increasing the TFR population and restoring their balance with TFH cells, vitamin D3 treatment helped regulate this immune response. Additionally, the infusion boosted the production of anti-inflammatory substances while decreasing those linked to inflammation, suggesting a potential new avenue for treating autoimmune hepatitis. Overall, these findings indicate that vitamin D3-modulated dendritic cells could be a promising strategy for managing autoimmune conditions like AIH.
Read More

Most Useful Reviews

9
Significant improvement
11 people found this helpful
I purchased this for my mother, and it’s been remarkable. The combination within one capsule is robust, boosting her vitamin D levels significantly from 26 ng/ml to 78 ng/ml. I will definitely order it again.
Read More
9
Boosts energy levels
6 people found this helpful
This vitamin D is exceptional! I struggled with allergies, including itching and rash, but everything improved with this. After consuming it for two months, I've felt energised, waking up easily and no longer experiencing daytime sleepiness. The combination of vitamin K and iodine seems to work wonders. I highly recommend it!
Read More
9
Significant improvement
2 people found this helpful
This product provides essential vitamin D and necessary cofactors for excellent absorption. It's crucial for maintaining good health. I’ve experienced a substantial improvement in wellbeing in just a short period of time. I’ll definitely order more for myself and my family!
Read More

Medical Researches

SCIENTIFIC SCORE
Possibly Effective
Based on 16 Researches
7.5
  • All Researches
9
Vitamin D3 mitigates autoimmune thyroiditis
Our research aimed to understand how vitamin D3 affects autoimmune thyroiditis, particularly in the context of Hashimoto's thyroiditis, which is characterized by low levels of vitamin D3 in patients. We induced a model of autoimmune thyroiditis in female mice and treated them with vitamin D3 to see if it could alleviate the symptoms of this condition.

After 8 weeks of treatment, we observed that vitamin D3 significantly improved the condition of the thyroid in these mice. The inflammation that commonly accompanies autoimmune thyroiditis decreased, and levels of thyroid autoantibodies, which indicate the severity of the disorder, also dropped. Notably, the application of vitamin D3 inhibited the activity of harmful immune cells while promoting the function of protective cells, providing a better balance in the immune response.

Overall, our findings suggest that vitamin D3 supplementation could be a promising strategy to manage autoimmune thyroiditis by restoring immune balance and reducing inflammation. This not only enhances our understanding of the disease but also opens up potential avenues for treatment in humans facing similar issues with autoimmune disorders.
Read More
We explored an intriguing instance of IgG4-related disease (IgG4-RD) manifesting as Mikulicz syndrome in an 85-year-old male patient. This condition usually involves significant systemic symptoms, yet our patient exhibited primarily local manifestations, specifically bilateral dacryoadenitis and orbital pseudotumor, without major organ complications.

Interestingly, despite normal serum IgG4 levels, which were below 135 mg/dL, the clinical and imaging findings strongly suggested the diagnosis of IgG4-RD. This scenario underscores the importance of undertaking a biopsy for accurate diagnosis. Histopathological examination revealed notable signs, such as a dense lymphoplasmacytic infiltrate and storiform fibrosis, with a considerable percentage of IgG4-positive cells, ultimately confirming our diagnosis.

We observed that treatment with prednisone, alongside azathioprine for long-term control, was effective. To mitigate the risk of glucocorticoid-induced osteoporosis, we added calcium and vitamin D3 supplementation. Remarkably, the patient showed significant clinical improvement within just 24 hours, with resolution of orbital and glandular symptoms over the following year. There was a complete recovery of vision and no relapses, with only minor dry eye as a long-term concern.

This case demonstrates the necessity of considering IgG4-RD even when serum IgG4 levels are normal and highlights the role of histopathology in diagnosis. Furthermore, it showcases the effectiveness of corticosteroids as a first-line treatment in managing this condition.
Read More
We examined the effects of calcitriol, an active form of vitamin D3, on mesenchymal stem cells (MSCs) in a model of rheumatoid arthritis. To do this, we induced arthritis in BALB/c mice and divided them into three groups: those without treatment, those treated with untreated MSCs, and those treated with calcitriol-exposed MSCs.

After conducting our experiments, we found that MSCs treated with calcitriol demonstrated improved regulatory functions and inhibited inflammatory responses more effectively than untreated MSCs. Specifically, we observed differences in the behavior of immune cells, with calcitriol-treated cells showing reduced levels of certain inflammatory cytokines, like INF-γ and IL-17, while increasing beneficial cytokines such as IL-4, IL-10, and TGF-β.

These findings suggest that vitamin D3 may play an important role in moderating the immune response in autoimmune conditions like rheumatoid arthritis, potentially offering a pathway for more effective treatment options.
Read More
We aimed to understand how vitamin D3, specifically its active form 1,25(OH)D, affects autoimmune hepatitis (AIH), a complex autoimmune disease that causes liver damage. Researchers focused on the role of a special type of immune cell known as dendritic cells (DCs), which are influenced by vitamin D3 to promote a more balanced immune response.

Through our investigation using a mouse model, we observed that injecting these vitamin D3-modulated dendritic cells, which overexpress a molecule called PD-L1, significantly lessened liver injury and severity of autoimmune hepatitis. This treatment appeared to correct the imbalance between two types of T cells: regulatory T cells (TFR) and follicular helper T cells (TFH).

By increasing the TFR population and restoring their balance with TFH cells, vitamin D3 treatment helped regulate this immune response. Additionally, the infusion boosted the production of anti-inflammatory substances while decreasing those linked to inflammation, suggesting a potential new avenue for treating autoimmune hepatitis. Overall, these findings indicate that vitamin D3-modulated dendritic cells could be a promising strategy for managing autoimmune conditions like AIH.
Read More
9
Vitamin D impacts autoimmune treatment
We investigated the effects of Vitamin D modulation on autoimmune prostatitis using a mouse model. In this study, we focused on how changes in gut microbiota influence the immune response, specifically looking at how vitamin D can help shift macrophage polarization—key players in the immune system—from a pro-inflammatory state (M1) to a more healing state (M2).

We observed that treatment with Eriocalyxin B (EriB), known for its anti-inflammatory properties, significantly reduced prostate inflammation in these mice. Our findings indicate that EriB not only altered the gut microbiome but also enhanced the absorption of vitamin D, contributing to a shift in macrophage phenotype. This suggests that the immune state of macrophages, altered through gut bacteria and vitamin D levels, plays a crucial role in managing autoimmune prostatitis.

Notably, fecal transplantation from EriB-treated mice resulted in a marked reduction in inflammatory markers and further supported the macrophage polarization effect. This is the first time we connected gut microbiota and vitamin D as pivotal factors in the treatment of autoimmune disorders like chronic prostatitis, highlighting a new therapeutic pathway. Overall, our research emphasizes the importance of vitamin D in modulating autoimmune responses through gut health.
Read More

User Reviews

USERS' SCORE
Good
Based on 32 Reviews
8
  • All Reviews
  • Positive Reviews
  • Negative Reviews
9
Significant improvement
11 people found this helpful
I purchased this for my mother, and it’s been remarkable. The combination within one capsule is robust, boosting her vitamin D levels significantly from 26 ng/ml to 78 ng/ml. I will definitely order it again.
Read More
9
Boosts energy levels
6 people found this helpful
This vitamin D is exceptional! I struggled with allergies, including itching and rash, but everything improved with this. After consuming it for two months, I've felt energised, waking up easily and no longer experiencing daytime sleepiness. The combination of vitamin K and iodine seems to work wonders. I highly recommend it!
Read More
9
Significant improvement
2 people found this helpful
This product provides essential vitamin D and necessary cofactors for excellent absorption. It's crucial for maintaining good health. I’ve experienced a substantial improvement in wellbeing in just a short period of time. I’ll definitely order more for myself and my family!
Read More
9
Thyroid support
2 people found this helpful
The excellent combination of vitamin D, K, and iodine helps maintain my immunity and supports my thyroid gland. I am planning to reorder.
Read More
0
High iodine concerns
2 people found this helpful
I was drawn to this for its high vitamin D with K. However, I should have checked the iodine content first! Having Hashimoto's disorder, the iodine levels are concerning. I’ll have to dispose of the four unopened bottles as I wouldn’t feel right giving them away, even to those without thyroid conditions. I’ve read several books on Hashimoto's, and all highlight the importance of avoiding iodine supplements.
Read More

Frequently Asked Questions

9
Health improvements
1 people found this helpful
A very high-quality product! After two months of use, my menstrual cycle normalised, and I've experienced less hair loss and fatigue. After four months, tests showed my TSH levels are normal. My endocrinologist approves these vitamins; hence, I highly recommend them.
9
Life-changing effect
1 people found this helpful
After being diagnosed with a severe vitamin D deficiency, I began taking this supplement each morning. It fundamentally changed my life—my mood improved, I felt energised to work, and I ventured outside more. When I stopped for two weeks, my condition worsened. I will continue with this product.
9
Significant improvement
11 people found this helpful
I purchased this for my mother, and it’s been remarkable. The combination within one capsule is robust, boosting her vitamin D levels significantly from 26 ng/ml to 78 ng/ml. I will definitely order it again.
9
Boosts energy levels
6 people found this helpful
This vitamin D is exceptional! I struggled with allergies, including itching and rash, but everything improved with this. After consuming it for two months, I've felt energised, waking up easily and no longer experiencing daytime sleepiness. The combination of vitamin K and iodine seems to work wonders. I highly recommend it!
9
Thyroid support
2 people found this helpful
The excellent combination of vitamin D, K, and iodine helps maintain my immunity and supports my thyroid gland. I am planning to reorder.
0
High iodine concerns
2 people found this helpful
I was drawn to this for its high vitamin D with K. However, I should have checked the iodine content first! Having Hashimoto's disorder, the iodine levels are concerning. I’ll have to dispose of the four unopened bottles as I wouldn’t feel right giving them away, even to those without thyroid conditions. I’ve read several books on Hashimoto's, and all highlight the importance of avoiding iodine supplements.
9
Improved immunity
1 people found this helpful
L.E. vitamin D&K has been my choice throughout the pandemic, and I’m pleased to note that taking between 5k and 10K a day has helped preserve my health, as my doctor remarked when she inquired about my methods to enhance my immunity. My son, a long-time supporter of Life Extension, encouraged my decision, and I also take Vitamin C and Super Selenium. I love your publication, which I read several times to keep up with new information. Keep enlightening me!
0
Hormonal imbalance
2 people found this helpful
I find this product effective in maintaining my vitamin D and K levels without needing to take them separately. However, I consistently monitor my levels, and I noticed an increase in TSH, which prompted a visit to the endocrinologist. Upon reviewing the iodine dosage, she advised discontinuation. After three months, my levels normalised. This iodine dosage significantly affected my hormones.
9
Vitamin D3 mitigates autoimmune thyroiditis
Our research aimed to understand how vitamin D3 affects autoimmune thyroiditis, particularly in the context of Hashimoto's thyroiditis, which is characterized by low levels of vitamin D3 in patients. We induced a model of autoimmune thyroiditis in female mice and treated them with vitamin D3 to see if it could alleviate the symptoms of this condition.

After 8 weeks of treatment, we observed that vitamin D3 significantly improved the condition of the thyroid in these mice. The inflammation that commonly accompanies autoimmune thyroiditis decreased, and levels of thyroid autoantibodies, which indicate the severity of the disorder, also dropped. Notably, the application of vitamin D3 inhibited the activity of harmful immune cells while promoting the function of protective cells, providing a better balance in the immune response.

Overall, our findings suggest that vitamin D3 supplementation could be a promising strategy to manage autoimmune thyroiditis by restoring immune balance and reducing inflammation. This not only enhances our understanding of the disease but also opens up potential avenues for treatment in humans facing similar issues with autoimmune disorders.
We observed a fascinating interplay between vitamin D3 and immune responses in patients with multiple sclerosis (MS), an autoimmune disorder that leads to significant neurological damage. Our focus was on a type of immune cell called tolerogenic dendritic cells (tolDCs), which help maintain a balance in the immune system. In our study, we used monocytes from both healthy donors and treatment-naive MS patients to assess how these cells behaved under different conditions.

Our findings revealed that tolDCs derived from MS patients had reduced tolerogenic properties when compared to their healthy counterparts. To our surprise, we found that direct activation of the aryl hydrocarbon receptor (AhR), a key player in immune regulation, could restore the tolerogenic features of MS patient-derived tolDCs. Furthermore, when we combined this approach with a treatment known as dimethyl fumarate (DMF), the results were even more promising.

The combination therapy of DMF and vitamin D3-tolDCs not only improved the tolerogenic effects but also showed better results in an experimental model of MS than using either treatment alone. This suggests that we may have a novel and effective strategy for enhancing immune tolerance in autoimmune diseases like MS.

Overall, our research indicates that vitamin D3, when used alongside DMF, could offer a new pathway for treatment, potentially minimizing the need for broader immunosuppression. This discovery opens up exciting possibilities for better management of autoimmune conditions in the future.
In our exploration of vitamin D3's role in autoimmune hepatitis (AIH), we conducted a thorough study using a large patient database to highlight how vitamin D deficiency affects those struggling with this condition.

We found that individuals with low levels of vitamin D, especially those below the threshold of 20 ng/mL, faced significantly worse health outcomes compared to their counterparts who had sufficient vitamin D levels. This included a staggering increase in the likelihood of all-cause mortality, hospitalizations, and even the need for liver transplants.

While the study set out to uncover the potential benefits of vitamin D3 treatment, it lacked the necessary details to isolate its direct effects. Despite confirming that vitamin D deficiency is linked to serious complications in AIH, we were unable to draw firm conclusions regarding how vitamin D3 treatment might specifically improve patient outcomes.

Overall, our findings signal a compelling call for further research into the benefits of vitamin D3 supplementation for individuals battling autoimmune diseases like AIH, paving the way for possibly critical health interventions.
We delved into the relationship between vitamin D3 and autoimmune thyroiditis, particularly Hashimoto's thyroiditis (HT). This condition involves the body attacking its own thyroid tissue due to a malfunctioning immune system. Our focus was on how vitamin D3 might influence this autoimmune disorder and whether its supplementation could mitigate the disease.

Research indicates that individuals with HT often have lower levels of vitamin D compared to those without the condition. When we examined cases where patients with HT and vitamin D deficiency received vitamin D3 supplementation, we noticed a promising trend. Specifically, it was found that thyroid autoantibody titers, which are markers of immune response against the thyroid, significantly decreased in these patients following supplementation.

However, it’s important to note that while these findings are encouraging, the overall understanding of vitamin D3’s role in treating autoimmune thyroid diseases is still developing. More rigorous studies, specifically randomized, double-blind, placebo-controlled trials with longer follow-up durations, are necessary to truly grasp the benefits of vitamin D3 in this context.

References

  1. Vernerová L, Vokurková M, Laiferová NA, Nemec M, Špiritović M, et al. Vitamin D and its receptor in skeletal muscle are associated with muscle disease manifestation, lipid metabolism and physical fitness of patients with myositis. Arthritis Res Ther. 2025;27:48. 10.1186/s13075-025-03516-9
  2. Wang CM, Chen YJ, Yang BC, Yang JW, Wang W, et al. Supplementation with active vitamin D3 ameliorates experimental autoimmune thyroiditis in mice by modulating the differentiation and functionality of intrathyroidal T-cell subsets. Front Immunol. 2025;16:1528707. 10.3389/fimmu.2025.1528707
  3. Mendoza-Vargas LÁ, Sevilla-Fuentes S, Bautista-Becerril B, Berthaúd-González B, Falfán-Valencia R, et al. IgG4-RD-Associated Mikulicz Syndrome Without Classic Systemic Involvement-A Case Report. J Clin Med. 2025;14. 10.3390/jcm14030958
  4. Rafati A, Ramezani R, Esmaeili Gouvarchin Ghaleh H, Bahrami S, Alvanegh AG, et al. Calcitriol Treated Mesenchymal Stem Cells Modulated Immune Response in Collagen-Induced Rheumatoid Arthritis in BALB/c Mice. Transplant Proc. 2025;57:355. 10.1016/j.transproceed.2024.12.020
  5. Kilani Y, Alsakarneh S, Madi MY, Mosquera DAG, Ferreira MN, et al. Autoimmune Hepatitis and Vitamin D Deficiency: A Nationwide Perspective. Aliment Pharmacol Ther. 2025;61:682. 10.1111/apt.18438
  6. Dai J, Song J, Chen X, Ding F, Ding Y, et al. 1,25(OH)D-treated mouse bone marrow-derived dendritic cells alleviate autoimmune hepatitis in mice by improving TFR/TFH imbalance. Immunopharmacol Immunotoxicol. 2025;47:59. 10.1080/08923973.2024.2435314
  7. Wielińska J, Górna K, Świerkot J, Bugaj B, Kolossa K, et al. Polymorphic Variants in the Vitamin D Receptor and Clinical Parameters of Rheumatoid Arthritis Patients Undergoing Anti-TNF Treatment. Arch Immunol Ther Exp (Warsz). 2024;72. 10.2478/aite-2024-0023
  8. Yu ZQ, Du HX, Gao S, Liang CZ. Eriocalyxin B ameliorated experimental autoimmune prostatitis via modulation of macrophage polarization through gut microbiota-mediated vitamin D alteration. Phytomedicine. 2024;135:156191. 10.1016/j.phymed.2024.156191
  9. Fondelli F, Willemyns J, Domenech-Garcia R, Mansilla MJ, Godoy-Tena G, et al. Targeting aryl hydrocarbon receptor functionally restores tolerogenic dendritic cells derived from patients with multiple sclerosis. J Clin Invest. 2024;134. 10.1172/JCI178949
  10. Grove-Laugesen D, Ebbehoj E, Watt T, Hansen KW, Rejnmark L. Changes in bone density and microarchitecture following treatment of Graves' disease and the effects of vitamin D supplementation. A randomized clinical trial. Osteoporos Int. 2024;35:2153. 10.1007/s00198-024-07241-y
  11. Zhang Q, He X, Chen W, Jiu J, Gao C, et al. Vitamin D3 attenuates autoimmune thyroiditis by regulating Th17/Treg cell differentiation via YAP/JAK1/STAT1 axis. Immunol Lett. 2024;269:106890. 10.1016/j.imlet.2024.106890
  12. Rodi M, de Lastic AL, Panagoulias I, Aggeletopoulou I, Kelaidonis K, et al. Myelin Oligodendrocyte Glycoprotein (MOG)35-55 Mannan Conjugate Induces Human T-Cell Tolerance and Can Be Used as a Personalized Therapy for Multiple Sclerosis. Int J Mol Sci. 2024;25. 10.3390/ijms25116092
  13. Maghbooli Z, Shirvani A, Moghadasi AN, Varzandi T, Hamtaei Ghashti S, et al. Investigating the effects of 25-hydroxyvitamin D3 on clinical outcomes in multiple sclerosis patients: A randomized, double-blind clinical trial- a pilot study. Mult Scler Relat Disord. 2024;87:105673. 10.1016/j.msard.2024.105673
  14. Fasihi M, Samimi-Badabi M, Robat-Jazi B, Bitarafan S, Moghadasi AN, et al. Immunoregulatory Effects of the Active Form of Vitamin D (Calcitriol), Individually and in Combination with Curcumin, on Peripheral Blood Mononuclear Cells (PBMCs) of Multiple Sclerosis (MS) Patients. Antiinflamm Antiallergy Agents Med Chem. 2024;23:138. 10.2174/0118715230293847240314073359
  15. Durá-Travé T, Gallinas-Victoriano F. Autoimmune Thyroiditis and Vitamin D. Int J Mol Sci. 2024;25. 10.3390/ijms25063154
  16. Qu F, Zhang M, Weinstock-Guttman B, Zivadinov R, Qu J, et al. An ultra-sensitive and high-throughput trapping-micro-LC-MS method for quantification of circulating vitamin D metabolites and application in multiple sclerosis patients. Sci Rep. 2024;14:5545. 10.1038/s41598-024-55939-0
image