Overview

SCIENTIFIC SCORE
Possibly Effective
Based on 17 Researches
7.1
USERS' SCORE
Moderately Good
Based on 43 Reviews
7.4
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

We looked into the growing concern of iodine deficiency hypothyroidism among children in the United States. This condition, which can lead to cognitive and physical impairments, was thought to be largely eliminated thanks to universal salt iodization started in the 1920s. However, recent trends suggest that iodine deficiency could be reappearing due to increased use of noniodized salts, lower iodine levels in dairy, and dietary restrictions like veganism or food allergies.

Over an 18-month period, we documented a series of cases where three children were diagnosed with iodine deficiency hypothyroidism despite having no underlying thyroid dysfunction. Their clinical presentations varied significantly—some had large goiters while others showed mild or no goiter at all. The results of their biochemical tests also highlighted a range of thyroid-stimulating hormone elevations.

Importantly, all patients returned to normal thyroid function following iodine supplementation. We propose that measuring spot urine iodine levels alongside elevated serum thyroglobulin could serve as a simpler and effective diagnostic approach, moving away from the more complex 24-hour urinary iodine tests. Our findings shine a light on the necessity of addressing iodine deficiency in today’s dietary landscape.
Read More
9
Vitamin D3 reduces thyroid autoimmunity
We explored the potential effects of vitamin D3, or cholecalciferol, on individuals diagnosed with Hashimoto's thyroiditis, a common form of hypothyroidism characterized by autoimmune responses that damage thyroid cells. Our study was a carefully structured clinical trial conducted over one year, which included 100 patients suffering from both Hashimoto's thyroiditis and vitamin D deficiency.

Divided into two groups, one received vitamin D3 supplements while the other was given a placebo. After eight weeks, we measured the levels of anti-thyroid peroxidase antibodies, which indicate autoimmune activity against the thyroid.

Our findings revealed a significant reduction in these antibody levels among patients who received vitamin D3, showcasing a 30.5% decrease compared to just a 16.5% decrease in the placebo group. This suggests that vitamin D3 supplementation may play a beneficial role in managing the autoimmune activity associated with hypothyroidism.

Overall, our research shows that addressing vitamin D deficiency might be an effective strategy to help manage Hashimoto's thyroiditis, which could encourage discussion about incorporating vitamin D as part of treatment plans for patients. Further research will be necessary to confirm these findings and explore the long-term benefits of vitamin D supplementation.
Read More
8
Vitamin D3 improves thyroid function
We evaluated the effects of vitamin D3 supplementation on hypothyroidism, specifically in patients with Hashimoto's thyroiditis (HT). Our analysis involved 12 randomized controlled trials, comparing the outcomes of individuals receiving vitamin D3 against those given a placebo or no treatment at all.

Through this thorough examination, we found that vitamin D3 did promote significant improvements in thyroid function and immune response. Specifically, we observed a reduction in two key antibodies: anti-thyroid peroxidase (TPO-Ab) and thyroglobulin antibody (TG-Ab). These reductions suggest a positive effect on the autoimmune process involved in Hashimoto's thyroiditis.

Additionally, we noted improvements in thyroid hormone levels, including free thyroxine (FT4) and free triiodothyronine (FT3), while thyroid-stimulating hormone (TSH) levels showed a decrease. These findings indicate that vitamin D3 supplementation may benefit thyroid health and help manage hypothyroidism more effectively.

For those considering vitamin D3 as a treatment option, particularly those who have been on vitamin D for longer than 12 weeks, the results suggest a more pronounced effect on improving antibody levels and thyroid function. Thus, there appears to be a compelling case for vitamin D3 as a supportive treatment in managing Hashimoto's thyroiditis and related hypothyroidism.
Read More

Most Useful Reviews

9
Chronic fatigue gone
1 people found this helpful
I bought this complex of vitamins D and K for the first time and am very pleased. It's particularly beneficial for those with thyroid issues like AIT and hypothyroidism. The antioxidants included have enhanced my well-being. I feel energetic, my mood is high, and chronic fatigue has vanished! I highly recommend these vitamins!!
Read More
10
Normalised thyroid function
A good product; taking one capsule of vitamin D has replenished and healed my thyroid gland due to the iodine content. I've been using it for about six months with positive results. My hypothyroidism has improved significantly without hormone therapy, despite what doctors said.
Read More
10
Improved mood
Fantastic supplement! The quality and ingredients are perfect for iodine loading. I noticed improvement in my mood within days. With hypothyroidism and iodine deficiency, I feel great and my bones and teeth are thanking me!
Read More

Medical Researches

SCIENTIFIC SCORE
Possibly Effective
Based on 17 Researches
7.1
  • All Researches
We looked into the growing concern of iodine deficiency hypothyroidism among children in the United States. This condition, which can lead to cognitive and physical impairments, was thought to be largely eliminated thanks to universal salt iodization started in the 1920s. However, recent trends suggest that iodine deficiency could be reappearing due to increased use of noniodized salts, lower iodine levels in dairy, and dietary restrictions like veganism or food allergies.

Over an 18-month period, we documented a series of cases where three children were diagnosed with iodine deficiency hypothyroidism despite having no underlying thyroid dysfunction. Their clinical presentations varied significantly—some had large goiters while others showed mild or no goiter at all. The results of their biochemical tests also highlighted a range of thyroid-stimulating hormone elevations.

Importantly, all patients returned to normal thyroid function following iodine supplementation. We propose that measuring spot urine iodine levels alongside elevated serum thyroglobulin could serve as a simpler and effective diagnostic approach, moving away from the more complex 24-hour urinary iodine tests. Our findings shine a light on the necessity of addressing iodine deficiency in today’s dietary landscape.
Read More
9.5
Iodine treatment for hypothyroidism
We explored the impact of iodine treatment on hypothyroidism, particularly focusing on a unique case involving a patient who had undergone total entero-colectomy. In this situation, standard methods of administering iodine, such as oral supplements, proved ineffective due to absorption challenges. Our approach utilized ethiodized oil, an iodine-rich contrast agent, which we injected intramuscularly.

We observed that this method not only addressed the patient's goiter but also sustained normal thyroid function for more than five years. The long half-life of ethiodized oil made it an ideal option for patients reliant on parenteral nutrition, who often struggle with iodine deficiency.

This study highlights a promising alternative for individuals facing similar nutritional challenges due to severe digestive issues. Overall, our findings suggest that tailored iodine administration could offer a viable solution for hypothyroidism linked to dietary deficiencies.
Read More
9
Vitamin D3 reduces thyroid autoimmunity
We explored the potential effects of vitamin D3, or cholecalciferol, on individuals diagnosed with Hashimoto's thyroiditis, a common form of hypothyroidism characterized by autoimmune responses that damage thyroid cells. Our study was a carefully structured clinical trial conducted over one year, which included 100 patients suffering from both Hashimoto's thyroiditis and vitamin D deficiency.

Divided into two groups, one received vitamin D3 supplements while the other was given a placebo. After eight weeks, we measured the levels of anti-thyroid peroxidase antibodies, which indicate autoimmune activity against the thyroid.

Our findings revealed a significant reduction in these antibody levels among patients who received vitamin D3, showcasing a 30.5% decrease compared to just a 16.5% decrease in the placebo group. This suggests that vitamin D3 supplementation may play a beneficial role in managing the autoimmune activity associated with hypothyroidism.

Overall, our research shows that addressing vitamin D deficiency might be an effective strategy to help manage Hashimoto's thyroiditis, which could encourage discussion about incorporating vitamin D as part of treatment plans for patients. Further research will be necessary to confirm these findings and explore the long-term benefits of vitamin D supplementation.
Read More
9
Vitamin D3 and iodine benefits
We investigated the potential benefits of vitamin D3 in treating hypothyroidism caused by high iodide intake in a study involving pregnant rats. The study involved adjusting iodide intake and supplementing with 1,25-dihydroxy-vitamin D (the active form of vitamin D) to see if these interventions could positively impact thyroid function and related complications.

The newborn rats were exposed to high levels of iodide initially, leading to thyroid dysfunction. After some weeks, we provided either iodide adjustment, vitamin D3 supplementation, or both to assess their effects.

Surprisingly, while vitamin D3 was combined with iodide adjustment, the study did not isolate the effect of vitamin D3 alone. However, we observed that both interventions increased levels of beneficial fatty acids, which are linked to improved thyroid function and lessened cholesterol issues in these rats.

These results suggest that implementing a proper iodide intake and vitamin D3 supplementation can improve thyroid health but do not clearly define vitamin D3's individual impact without additional research isolating its effects.
Read More
We assessed how effective radioactive iodine (RAI) treatment is for inducing hypothyroidism in adolescents with Graves' disease (GD). This treatment is often considered when initial therapies, like antithyroid drugs, do not yield lasting results.

In our examination, we reviewed the medical records of teenagers under 18 years old who received RAI treatment from January 2007 to December 2022. We identified 14 cases and noted their ages ranged from 9.8 to 17.3 years, with I131 doses varying between 5.8 and 15.0 mCi.

Remarkably, almost all patients responded positively within six months after treatment, with a cure rate of 86%. Most experienced hypothyroidism within three months, reinforcing the necessity of monitoring thyroid function early on. We did observe one case of temporary salivary gland inflammation.

Throughout the follow-up period of up to 13 years, there were no relapses, which speaks to the effectiveness and safety of RAI as an option for these young patients with GD.
Read More

User Reviews

USERS' SCORE
Moderately Good
Based on 43 Reviews
7.4
  • All Reviews
  • Positive Reviews
  • Negative Reviews
9
Chronic fatigue gone
1 people found this helpful
I bought this complex of vitamins D and K for the first time and am very pleased. It's particularly beneficial for those with thyroid issues like AIT and hypothyroidism. The antioxidants included have enhanced my well-being. I feel energetic, my mood is high, and chronic fatigue has vanished! I highly recommend these vitamins!!
Read More
10
Normalised thyroid function
A good product; taking one capsule of vitamin D has replenished and healed my thyroid gland due to the iodine content. I've been using it for about six months with positive results. My hypothyroidism has improved significantly without hormone therapy, despite what doctors said.
Read More
10
Improved mood
Fantastic supplement! The quality and ingredients are perfect for iodine loading. I noticed improvement in my mood within days. With hypothyroidism and iodine deficiency, I feel great and my bones and teeth are thanking me!
Read More
9
Increased efficiency
Endocrinologist approved! I have hypothyroidism, discovered during pregnancy, and I take iodine and hormones daily. I found this herbal preparation after taking 250 mg of iodomarin. The iodine dosage was shocking initially, yet my endocrinologist approved it. While I recommend being cautious with children, I feel energised after taking it. I noticed a significant boost in efficiency, especially after taking iodine in the morning to avoid insomnia. After a month, my levels returned to normal. Excellent product!
Read More
9
Effective combination
An excellent combination of vitamin D3 with K2 and marine iodine significantly aids those managing hypothyroidism.
Read More

Frequently Asked Questions

10
Improved mood
Fantastic supplement! The quality and ingredients are perfect for iodine loading. I noticed improvement in my mood within days. With hypothyroidism and iodine deficiency, I feel great and my bones and teeth are thanking me!
9
Increased efficiency
Endocrinologist approved! I have hypothyroidism, discovered during pregnancy, and I take iodine and hormones daily. I found this herbal preparation after taking 250 mg of iodomarin. The iodine dosage was shocking initially, yet my endocrinologist approved it. While I recommend being cautious with children, I feel energised after taking it. I noticed a significant boost in efficiency, especially after taking iodine in the morning to avoid insomnia. After a month, my levels returned to normal. Excellent product!
7.5
Expecting benefits
6 people found this helpful
I took this supplement while treating hypothyroidism and thankfully noticed results in over a month. My health was poor, but I hope continuing will be beneficial. I plan to return to it soon!
10
Normalised thyroid function
A good product; taking one capsule of vitamin D has replenished and healed my thyroid gland due to the iodine content. I've been using it for about six months with positive results. My hypothyroidism has improved significantly without hormone therapy, despite what doctors said.
1
Too much iodine
17 people found this helpful
Not suitable for hypothyroidism. I did not realise it contained 667% of the daily dose of iodine, which is unreasonable even for a healthy person without thyroid issues. My doctor explained that iodine should be increased gradually, starting from 100% of the daily dose. This supplement overloads the body with excessive iodine, which might cause an overactive thyroid.
9
Chronic fatigue gone
1 people found this helpful
I bought this complex of vitamins D and K for the first time and am very pleased. It's particularly beneficial for those with thyroid issues like AIT and hypothyroidism. The antioxidants included have enhanced my well-being. I feel energetic, my mood is high, and chronic fatigue has vanished! I highly recommend these vitamins!!
9
Indispensable dosage
Great dosage! An excellent 5000 units of vitamin D and 1000 units of iodine. This medication is essential for managing my hypothyroidism.
9
Normalised indicators
After taking one capsule each morning for two months, my vitamin D increased from 14 to 60. This complex was recommended for my hypothyroidism, and my antibodies decreased while thyroid hormone levels increased. It’s effective and convenient!
8
Vitamin D3 improves thyroid function
We evaluated the effects of vitamin D3 supplementation on hypothyroidism, specifically in patients with Hashimoto's thyroiditis (HT). Our analysis involved 12 randomized controlled trials, comparing the outcomes of individuals receiving vitamin D3 against those given a placebo or no treatment at all.

Through this thorough examination, we found that vitamin D3 did promote significant improvements in thyroid function and immune response. Specifically, we observed a reduction in two key antibodies: anti-thyroid peroxidase (TPO-Ab) and thyroglobulin antibody (TG-Ab). These reductions suggest a positive effect on the autoimmune process involved in Hashimoto's thyroiditis.

Additionally, we noted improvements in thyroid hormone levels, including free thyroxine (FT4) and free triiodothyronine (FT3), while thyroid-stimulating hormone (TSH) levels showed a decrease. These findings indicate that vitamin D3 supplementation may benefit thyroid health and help manage hypothyroidism more effectively.

For those considering vitamin D3 as a treatment option, particularly those who have been on vitamin D for longer than 12 weeks, the results suggest a more pronounced effect on improving antibody levels and thyroid function. Thus, there appears to be a compelling case for vitamin D3 as a supportive treatment in managing Hashimoto's thyroiditis and related hypothyroidism.
9
Vitamin D3 reduces thyroid autoimmunity
We explored the potential effects of vitamin D3, or cholecalciferol, on individuals diagnosed with Hashimoto's thyroiditis, a common form of hypothyroidism characterized by autoimmune responses that damage thyroid cells. Our study was a carefully structured clinical trial conducted over one year, which included 100 patients suffering from both Hashimoto's thyroiditis and vitamin D deficiency.

Divided into two groups, one received vitamin D3 supplements while the other was given a placebo. After eight weeks, we measured the levels of anti-thyroid peroxidase antibodies, which indicate autoimmune activity against the thyroid.

Our findings revealed a significant reduction in these antibody levels among patients who received vitamin D3, showcasing a 30.5% decrease compared to just a 16.5% decrease in the placebo group. This suggests that vitamin D3 supplementation may play a beneficial role in managing the autoimmune activity associated with hypothyroidism.

Overall, our research shows that addressing vitamin D deficiency might be an effective strategy to help manage Hashimoto's thyroiditis, which could encourage discussion about incorporating vitamin D as part of treatment plans for patients. Further research will be necessary to confirm these findings and explore the long-term benefits of vitamin D supplementation.
We explored the relationship between vitamin D supplementation and hypothyroidism through the D-Health Trial, a well-structured study involving over 21,000 Australian participants aged 60 and older. This trial randomly assigned participants to receive either a monthly dose of 60,000 international units of vitamin D or a placebo, allowing us to effectively assess any potential benefits of vitamin D on thyroid function.

Our analysis revealed that, during an average follow-up of 4.1 years, 293 participants developed hypothyroidism. Interestingly, the rates were similar between the groups, with 1.5% of those taking vitamin D and 1.7% of those on placebo developing the condition. Overall, vitamin D supplementation did not significantly lower the risk of hypothyroidism, as shown by the hazard ratio of 0.89.

However, we did notice a slight difference when analyzing the data by gender. While there was some evidence suggesting a potential benefit for females (with a hazard ratio of 0.78), no such effect was observed in males. Given the findings, it seems that vitamin D supplementation does not provide a clear protective effect against hypothyroidism overall, although the intriguing trend observed in females deserves further research to better understand its implications.

References

  1. Tang J, Shan S, Li F, Yun P. Effects of vitamin D supplementation on autoantibodies and thyroid function in patients with Hashimoto's thyroiditis: A systematic review and meta-analysis. Medicine (Baltimore). 2023;102:e36759. 10.1097/MD.0000000000036759
  2. Waterhouse M, Pham H, Rahman ST, Baxter C, Duarte Romero B, et al. The Effect of Vitamin D Supplementation on Hypothyroidism in the Randomized Controlled D-Health Trial. Thyroid. 2023;33:1302. 10.1089/thy.2023.0317
  3. Bhakat B, Pal J, Das S, Charaborty SK, SircarMedical NR. A Prospective Study to Evaluate the Possible Role of Cholecalciferol Supplementation on Autoimmunity in Hashimoto's Thyroiditis. J Assoc Physicians India. 2023;71:1.
  4. Liu Q, Zhang Y, Zhao H, Yao X. Increased Epoxyeicosatrienoic Acids and Hydroxyeicosatetraenoic Acids After Treatment of Iodide Intake Adjustment and 1,25-Dihydroxy-Vitamin D Supplementation in High Iodide Intake-Induced Hypothyroid Offspring Rats. Front Physiol. 2021;12:669652. 10.3389/fphys.2021.669652
  5. ElRawi HA, Ghanem NS, ElSayed NM, Ali HM, Rashed LA, et al. Study of Vitamin D Level and Vitamin D Receptor Polymorphism in Hypothyroid Egyptian Patients. J Thyroid Res. 2019;2019:3583250. 10.1155/2019/3583250
  6. Ucan B, Sahin M, Sayki Arslan M, Colak Bozkurt N, Kizilgul M, et al. Vitamin D Treatment in Patients with Hashimoto's Thyroiditis may Decrease the Development of Hypothyroidism. Int J Vitam Nutr Res. 2016;86:9. 10.1024/0300-9831/a000269
  7. Anaraki PV, Aminorroaya A, Amini M, Feizi A, Iraj B, et al. Effects of Vitamin D deficiency treatment on metabolic markers in Hashimoto thyroiditis patients. J Res Med Sci. 2017;22:5. 10.4103/1735-1995.199090
  8. Mansournia N, Mansournia MA, Saeedi S, Dehghan J. The association between serum 25OHD levels and hypothyroid Hashimoto's thyroiditis. J Endocrinol Invest. 2014;37:473. 10.1007/s40618-014-0064-y
  9. Kemmochi S, Fujimoto H, Woo GH, Hirose M, Nishikawa A, et al. Preventive effects of calcitriol on the development of capsular invasive carcinomas in a rat two-stage thyroid carcinogenesis model. J Vet Med Sci. 2011;73:655.
  10. van Oosterom AT, Kerkhoven P, Veltkamp JJ. Metabolism of the coagulation factors of the prothrombin complex in hypothyroidism in man. Thromb Haemost. 1979;41:273.
  11. van Oosterom AT, Mattie H, Hermens WT, Veltkamp JJ. The influence of the thyroid function on the metabolic rate of prothrombin, factor VII, and factor X in the rat. Thromb Haemost. 1976;35:607.
  12. Waśniowska J, Piątkowska E, Pawlicki P, Smoleń S, Kopeć A, et al. Comparative Analysis of Iodine Levels, Biochemical Responses, and Thyroid Gene Expression in Rats Fed Diets with Kale Biofortified with 5,7-Diiodo-8-Quinolinol. Int J Mol Sci. 2025;26. 10.3390/ijms26020822
  13. Cox SE, Wakeling J, Hall T, Williams TL. Survival of radioiodine treated hyperthyroid cats that are euthyroid and hypothyroid after treatment, and effect of levothyroxine supplementation on survival time of cats with iatrogenic hypothyroidism. J Vet Intern Med. 2025;39:e17295. 10.1111/jvim.17295
  14. He J, Dong Y, Chen X, Wang S, Shen Z, et al. Hypothyroidism induced by excessive-iodine is associated in humans with altered hsa-miR-199a-5p/HIF-1α axis and thyroglobulin. J Nutr Biochem. 2025;138:109841. 10.1016/j.jnutbio.2025.109841
  15. Seetharaman S, Sasidharan Pillai S, Ganta A, Millington K, Quintos JB, et al. Iodine Deficiency Hypothyroidism Among Children in the United States - 21st Century Resurgence?. AACE Clin Case Rep. 2024;10:236. 10.1016/j.aace.2024.08.003
  16. Chielens L, Nauwynck E, Bourgeois S, Staels W, Vanbesien J, et al. A Belgian single centre outcome study of radioiodine treatment in adolescents with Graves' disease. Sci Rep. 2024;14:31063. 10.1038/s41598-024-82052-z
  17. Belaid S, Raghu V, Alissa F, Rudolph J. Long lasting effect of intramuscular iodine injection in the treatment of goiter in an intestinal failure patient with complete entero-colectomy. JPGN Rep. 2024;5:561. 10.1002/jpr3.12117
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