Hashimoto's Thyroiditis and Vitamin D - multiple studies

Most studies agree: Hashimoto's Thyroiditis is associated with low Vitamin D

H vs H

HASHIMOTO'S: IS IT A THYROID PROBLEM OR AN IMMUNE PROBLEM?

Vitamin D Life pages with HASHIMOTO in title (8 as of Aug 2022)

This list is automatically updated

See also Vitamin D Life

• Hashimoto's thyroiditis helped by weekly 50,000 IU of vitamin D – RCT May 2019
• Hashimoto's thyroiditis 3.2 X more likely if low vitamin D – meta-analysis May 2019
• Autoimmune Thyroid Disease 3X more likely if low vitamin D – meta-analysis April 2015
  • Both Graves' disease and Hashimoto thyroiditis
• Sunshine vitamin and thyroid – Jan 2017
• Vitamin D and autoimmune thyroid diseases. – Jan 2011
  • Deficiency = 10 ng. 72% for those with autoimmune thyroid disease, 31% of controls
  • Examples: Graves disease and Hashimoto thyroiditis
• Long term Hashimoto's Thyroiditis has lower level of vitamin D – Jan 2013
• Graves' disease and Hashimoto's thyroiditis 1.5X less likely for each 2 ng more vitamin D – Sept 2015
• Graves Disease is 2.2X more likely with low vitamin D – meta-analysis May 2015
• Autoimmune Thyroid Disease 3X more likely if low vitamin D – meta-analysis April 2015
• Vitamin D and Primary Hyperparathyroidism – 2011, 2016
• 50,000 IU vitamin D weekly is safe and effective for Primary Hyperparathyroidism – Jan 2013
• Overview Thyroid and Vitamin D
• Vitamin D Resistance hypothesis confirmed by Coimbra high-dose vitamin D protocol – April 2021
  • Sometimes HT is a result of not enought Vitamin d in the blood getting to the tissues

VitaminDwiki - Thyroid and parathyroid category contains:

• 81 items in the category
• See also Overview Hyperparathyroidism and vitamin D
• Overview Thyroid and Vitamin D
• PTH 4470 items as of Feb 2020
• "GRAVES DISEASE" 428 items as of Feb 2020

Hashimoto’s thyroiditis meta-analysis (only 3 RCTs used Vitamin D3) - Jan 2024

Effects of vitamin D supplementation on autoantibodies and thyroid function in patients with Hashimoto’s thyroiditis A systematic review and meta-analysis
Medicine http://dx.doi.org/10.1097/MD.0000000000036759
Jiahao Tang, MMeda, Shuanghong Shan, MMeda, Fangping Li, MDa, Peng Yun, MMeda*

Background: Hashimoto's thyroiditis (HT) is the prevailing form of autoimmune thyroiditis and the leading cause of hypothyroidism in iodine-sufficient regions worldwide. This study aims to evaluate the efficacy of vitamin D supplementation on HT through a meta-analysis of randomized controlled trials (RCTs).

Methods: The databases searched included PubMed, and others. We included RCTs that the treatment group received vitamin D, while the control group received either a placebo or no treatment. The studies measured the baseline and endpoint levels of 25-hydroxyvitamin D [25(OH)D], thyroid-stimulating hormone (TSH), free thyroxine (FT4), free triiodothyronine (FT3), anti-thyroid peroxidase antibody (TPO-Ab), and thyroglobulin antibody (TG-Ab). We performed a meta-analysis to calculate the standardized mean difference (SMD) and 95% confidence interval (CI).

Results: A total of 12 studies involving 862 individuals were included. Vitamin D supplementation has a significant impact on reducing the titers of TPO-Ab (SMD = -1.084, 95% CI = -1.624 to -0.545) and TG-Ab (SMD = -0.996, 95% CI = -1.579 to -0.413) in patients with HT, and it also improves thyroid function by decreasing TSH level (SMD = -0.167, 95% CI = -0.302 to 0.031) and increasing FT3 (SMD = 0.549, 95% CI = 0.077-1.020) and FT4 (SMD = 0.734, 95% CI = 0.184-1.285) levels. Active vitamin D (calcitriol) significantly reduces the titer of TPO-Ab compared to naive forms of vitamin D (vitamin D2 or D3); treatment durations > 12 weeks result in a more effective reduction of TPO-Ab levels and a more significant increase in FT4 and FT3 levels in patients with HT (meta-regression P < .05).

Conclusion: Vitamin D supplementation may have beneficial effects on HT patients by modulating immune responses and improving thyroid function.
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Hashimoto’s thyroiditis and vitamin D - meta-analysis - Dec 2021

Effects of vitamin D on thyroid autoimmunity markers in Hashimoto’s thyroiditis: systematic review and meta-analysis
Jingwen Zhang, Yuting Chen, …, and Hong Li shanhong_li at 126.com
Journal of international Medical Research FREE PDF

Objective
To perform a meta-analysis of randomized controlled trials to evaluate the efficacy of vitamin D supplementation on thyroid autoimmunity markers in Hashimoto’s thyroiditis (HT).

Methods
This meta-analysis included randomized controlled clinical trials identified by a systematic search of electronic databases (PubMed®, MEDLINE®, EMBASE, The Cochrane Library, China National Knowledge Infrastructure) from inception to August 2020. All studies included patients with HT that received vitamin D supplementation irrespective of the doses administered or the duration of treatment. The primary and secondary outcome measures were thyroid peroxidase antibody (TPOAb) and/or thyroglobulin antibody (TGAb) titres.

Results
Eight studies (n = 652) were included. There was significant heterogeneity between the studies. Using a random-effect model, vitamin D supplementation reduced TPOAb titre (standardized mean difference [SMD]: –1.11; 95% confidence interval [CI]: 1–1.92, –0.29) and TGAb titre (SMD: –1.12; 95% CI: –1.96, –0.28). A subgroup analysis demonstrated that vitamin D supplementation for >3 months resulted in a decrease in TPOAb titre (SMD: –1.66, 95% CI: –2.91, –0.41) but treatment ≤3 months was ineffective. Treatment with vitamin D3 decreased TPOAb titre (SMD: –1.48; 95% CI: –2.53, –0.42) whereas vitamin D did not.

Conclusion
These data suggest that vitamin D reduces autoantibody titre in patients with HT.

Those with Hashimoto's thyroiditis are 3.2 X more likely to have <20 ng - meta-analysis April 2020

Serum 25-hydoxyvitamin D concentrations in relation to Hashimoto's thyroiditis: a systematic review, meta-analysis and meta-regression of observational studies
"HT showed an odds ratio (OR) of 3.21 (1.94-5.3; P = 5.7 × 10-6) for 25(OH)D deficiency (cut-off 20 ng/mL) against healthy controls."
Mario Štefanić 1, Stana Tokić 2 DOI: 10.1007/s00394-019-01991-w

Vitamin D supplementation (1200-4000 IU) reduced HT - Sept 2015

Is vitamin D related to pathogenesis and treatment of Hashimoto's thyroiditis?
Hell J Nucl Med. 2015 Sep-Dec;18(3):222-7.
Mazokopakis EE1, Papadomanolaki MG, Tsekouras KC, Evangelopoulos AD, Kotsiris DA, Tzortzinis AA.
1Department of Internal Medicine, Naval Hospital of Crete, K. Mitsotaki 36, Chania 73 132,Crete, Greece. emazokopakis at yahoo.gr.

OBJECTIVE:
The aim of this study was to investigate vitamin D status by measuring serum 25(OH)D levels in euthyroid patients with Hashimoto's thyroiditis (HT) who lived and worked on the sunny island of Crete, Greece, and to evaluate whether vitamin D3 supplementation is beneficial for the management of HT patients with vitamin D deficiency.

SUBJECTS AND METHODS:
We studied 218 HT patients, euthyroid Caucasian Cretan Greek citizens: 180 females and 38 males. Among these patients, 186 (85.3%) had vitamin D deficiency defined as serum 25(OH)D levels < 30 ng/mL. The mean age of all these 218 HT patients was 35.3 ± 8.5 years. The mean age of the 186 vitamin D deficient HT patients (173 females and 13 males) was 37.3 ± 5.6 years. The 186 vitamin D deficient HT patients received vitamin D3 (cholecalciferol, CF) orally, 1200-4000 IU, every day for 4 months aiming to maintain serum 25(OH)D levels ≥ 40 ng/mL. Anthropometric characteristics (height, weight, waist circumference), systolic and diastolic blood pressure, serum concentration of 25(OH)D, thyrotropin (TSH), free thyroxine (FT4), anti-thyroid peroxidase (anti-TPO), antithyroglobulin (anti-TG), calcium and phosphorus levels and thyroid and kidney sonographic findings were recorded and measured before and after CF administration.

RESULTS:
There was a significant negative correlation only between serum 25(OH)D levels and anti-TPO levels among all 218 HT patients. Also, anti-TPO levels were significantly higher in 186/218 vitamin D deficient HT patients compared to 32/218 HT patients with no vitamin D deficiency (364 ± 181IU/mL versus 115.8 ± 37.1IU/mL, P<0.0001).
Supplementation of CF in 186 vitamin D deficient HT patients caused a significant decrease (20.3%) in serum anti-TPO levels.
Although at the end of the 4 months period of the study body mass index (BMI), serum anti-TG and TSH levels decreased by 2.2%, 5.3% and 4% respectively, these differences were not significant.
No changes in the sonographic findings were observed.

CONCLUSION:
The majority (85.3%) of the Greek Caucasian patients with HT studied who lived and worked in Crete had low serum 25(OH)D levels inversely correlated with serum anti-TPO thyroid antibodies. After 4 months of CF supplementation in the 186 HT patients with vitamin D deficiency, a significant decrease (20.3%) of serum anti-TPO levels was found. These findings suggest that vitamin D deficiency may be related to pathogenesis of HT and that its supplementation could contribute to the treatment of patients with HT.
PMID: 26637501
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Hashimoto's Thyroiditis 2.3X more likely if low vitamin D - June 2015

J Clin Res Pediatr Endocrinol. 2015 Jun 5;7(2):128-33. doi: 10.4274/jcrpe.2011.
Vitamin D Deficiency and Hashimoto's Thyroiditis in Children and Adolescents: a Critical Vitamin D Level for This Association?
Evliyaoğlu O1, Acar M, Özcabı B, Erginöz E, Bucak F, Ercan O, Kucur M.
Author information
1İstanbul University Cerrahpaşa Faculty of Medicine, Department of Pediatric Endocrinology, İstanbul, Turkey Phone: +90 533 633 15 64 E-mail: olcayevliyaoglu at hotmail.com.

OBJECTIVE: Vitamin D has been suggested to be active as an immunomodulator in autoimmune diseases such as Hashimoto's thyroiditis (HT). The goal of the present study was to investigate the vitamin D status in HT patients.

METHODS: This prevalence case-control study was conducted on 90 patients with HT (of ages 12.32±2.87 years) and 79 age-matched healthy controls (11.85±2.28 years). Serum 25-hydroxyvitamin D3 [25(OH)D3] levels were measured in all 169 subjects.

RESULTS: The prevalence of vitamin D deficiency in HT patients (64 of 90; 71.1%) was significantly higher than that in the control group (41 of 79; 51.9%) (p=0.025). Mean serum 25(OH)D3 level in the HT group was significantly lower compared to the control group (16.67±11.65 vs. 20.99±9.86 ng/mL, p=0.001). HT was observed 2.28 times more frequently in individuals with 25(OH)D3 levels <20 ng/mL (OR: 2.28, CI: 1.21-4.3).

CONCLUSION: Vitamin D deficiency is associated with HT in children and adolescents.
Levels lower than 20 ng/mL seem to be critical.
The mechanism for this association is not clear.

92% of Hashimoto’s patients had Vitamin D deficiency - Jan 2015

hypothyroidmom

Relative Vitamin D Insufficiency in Hashimoto's Thyroiditis (2011)

Gonca Tamer,1; Safiye Arik,2; Ismet Tamer,3 and Damla Coksert2
1 Department of Endocrinology and Metabolism, Goztepe Education and Research Hospital, Istanbul, Turkey. hgtamer at yahoo.com
2 Department of Internal Medicine, Goztepe Education and Research Hospital, Istanbul, Turkey.
3 Department of Family Medicine, Kartal Education and Research Hospital, Istanbul, Turkey.

Background: Vitamin D insufficiency, defined as serum levels of 25-hydroxyvitamin D [25(OH)D3] lower than 30?ng/mL, has been reported to be prevalent in several autoimmune diseases such as multiple sclerosis and type 1 diabetes mellitus. The goal of the present study was to assess whether vitamin D insufficiency is also a feature of Hashimoto's thyroiditis (HT).

Methods: We performed a prevalence case–control study that included 161 cases with HT and 162 healthy controls.
Serum levels of 25(OH)D3, calcium, phosphorus, and parathyroid hormone were measured in all 323 subjects.

Results: The prevalence of vitamin D insufficiency in HT cases (148 of 161, 92%) was significantly higher than that observed in healthy controls (102 of 162, 63%, p?<?0.0001). Among HT cases, the prevalence rate of vitamin D insufficiency showed a trend to be higher in patients with overt hypothyroidism (47 of 50, 94%) or subclinical hypothyroidism (44 of 45, 98%) than in those with euthyroidism (57 of 66, 86%), but the differences were not significant (p?=?0.083).

Conclusion: Vitamin D insufficiency is associated with HT. Further studies are needed to determine whether vitamin D insufficiency is a casual factor in the pathogenesis of HT or rather a consequence of the disease.

Hashimoto's autoimmune thyroiditis and vitamin D deficiency. Current aspects. (Feb 2014)

Hell J Nucl Med. 2014 Feb 21. pii: s002449910120.
Mazokopakis EE1, Kotsiris DA.
Iroon Polytechniu 38A, Chania, 73 132, Crete, Greece. emazokopakis at yahoo.gr.

Hashimoto's thyroiditis (HT) is a chronic autoimmune thyroid disease caused by an interaction between genetic factors and environmental conditions, both of which are not yet completely understood. The significant association between vitamin D deficiency and HT has been investigated regarding the immune role of this hormone. In HT, an immunologic reaction is triggered when thyrocytes express major histocompatibility complex (MHC) class II surface HLA-DR antigens, a process induced by the production from T helper (Th)1 type lymphocytes, of inflammatory cytokines (especially IFN-γ), which may be inhibited by 1,25[OH]2D. Genetic polymorphism of vitamin D receptor (VDR), binding protein (DBP) and of 1α-hydroxylase (CYP1α) may also predispose to the development of HT.

Considering current evidence, presented in this review, screening for vitamin D deficiency and careful vitamin D supplementation, when required, may be recommended for patients with HT.

Further research is needed in patients with HT in order to investigate the mechanisms by which vitamin D affects autoimmunity and also to evaluate the cost-effectiveness of vitamin D supplementation and to suggest the possible optimal dose treatment.
PMID: 24563883
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Risk of Hashimoto's Thyroiditis reduced 19 percent for each 5 ng increase in vitamin D – March 2014

The association between serum 25OHD levels and hypothyroid Hashimoto’s thyroiditis
Journal of Endocrinological Investigation, March 2014
Nasrin Mansournia, Mohammad Ali Mansournia, Sandra Saeedi, Jafar Dehghan

Background
Vitamin D is shown to be a potent immunomodulator. Considering the potential role of low serum vitamin D levels in autoimmune disorder, we evaluated the association between Hashimoto’s thyroiditis (HT) (with subclinical or overt hypothyroidism) and serum 25-hydroxyvitamin D (25OHD) levels in an Iranian population.

Methods
A total number of 86 individuals were enrolled. The case group included 41 patients with hypothyroid HT (overt or subclinical). The control group comprised 45 healthy euthyroid persons. Serum 25OHD levels were measured in all subjects.

Results
The case:control ratio of geometric means of 25OHD levels was 0.66 (95 % CI: 0.49–0.90; P = 0.008). There was a significant inverse association between serum 25OHD levels and HT (OR: 0.81 for 5 ng/ml increase in 25OHD level, 95 % CI: 0.68–0.96; P = 0.018). This association remained significant after adjustment for potential confounding factors including age, sex and BMI.

Conclusions
Our study suggested that higher serum 25OHD levels was associated with decreased risk of HT so that each 5 ng/ml increase in the serum 25OHD levels results in 19 % decrease in odds of HT.
References

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8. Munger KL, Levin LI, Hollis BW, Howard NS, Ascherio A (2006) Serum 25-hydroxyvitamin D levels and risk of multiple sclerosis. JAMA 296(23):2832–2838 CrossRef
9. van der Mei IA, Ponsonby AL, Dwyer T, Blizzard L, Taylor BV, Kilpatrick T et al (2007) Vitamin D levels in people with multiple sclerosis and community controls in Tasmania. Aust J Neurol 254(5):581–590 CrossRef
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No difference in Frequency of Hashimoto's thyroiditis with Vitamin D level in Turkey - 2014

Note: perhaps no difference because very few people in Turkey have enough vitamin D
Frequency of Hashimoto's thyroiditis in women with vitamin D deficiency: A cross sectional study
American Journal of Internal Medicine, 2014; 2(3): 44-48
Published online May 20, 2014 (http://www.sciencepublishinggroup.eom/j/ajim) doi: 10.11648/j.ajim.20140203.12
Tayyibe Saler , §akir Ozgiir Keskek ' , Suleyman Ahbab , Sedat Cakir , Giilay Ortoglu , Mehmet Bankir , Omer Arif Pamuk
department of Internal Medicine, Umraniye Training and Research Hospital, Istanbul, Turkey 2Department of Internal Medicine, Numune Training and Research Hospital Hospital, Adana, Turkey 3Department of Internal Medicine, Haseki Training and Research Hospital Hospital, Istanbul, Turkey drkeskek at yahoo.com (§. O. Keskek)

Objective: Vitamin D deficiency has been reported to be associated with different autoimmune diseases such as type 1 diabetes, rheumatoid arthritis and Crohn's disease. The aim of this study was to evaluate the association between Hashimoto's thyroiditis and vitamin D deficiency.
Material and Methods: This case-control study was carried out in tertiary hospitals from 2011 to 2012. A total of 198 female subjects were included, of whom 84 and 114 participants were healthy or had vitamin D deficiency, respectively. Serum vitamin D levels, parathyroid hormone concentrations thyroid hormone levels and thyroid auto-antibodies were measured in all subjects.
Results: Demographic characteristics of participants were not significantly different between the control and study groups (p > 0,05). Frequency of Hashimoto's thyroiditis was similar in both groups (p = 0.958). Thyroid auto-antibodies did not correlate with vitamin D levels (p > 0.05).

Conclusion: Although vitamin D deficiency is associated with some of autoimmune diseases, Hashimoto's thyroiditis was not found to be associated with vitamin D deficiency in female patients in this study.
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Hypothyroidism And Hashimoto's Thyroiditis - book 2013 - includes Vitamin D

A Groundbreaking, Scientific And Practical Treatment Approach
Amazon Dr. Zaidi
Note: I have not read this book, but his other books on Vitamin D are great

Low vitamin D status is associated with hypothyroid Hashimoto's thyroiditis. - July 2016

Hormones (Athens). 2016 Jul 11. doi: 10.14310/horm.2002.1681. [Epub ahead of print]
Kim D Department of Internal Medicine, Dankook University College of Medicine, Department of Kinesiologic Medical Science, Graduate, Dankook University, Cheonan, 330-714, Republic of Korea.

OBJECTIVE:
The association of low vitamin D status with autoimmune thyroid disease (AITD), which includes Hashimoto's thyroiditis (HT) and Graves' disease (GD), is controversial. The aim of this study was to investigate the correlation between vitamin D insufficiency and AITD, HT, and GD.

DESIGN:
Our cross-sectional study included patients who visited a tertiary hospital for thyroid evaluation or follow-up. A total of 776 patients in whom serum 25-hydroxyvitamin D [25(OH)D], thyroid function, and anti-thyroid antibodies had been measured were analyzed retrospectively. Vitamin D insufficiency was defined as serum 25(OH)D level <75 nmol/L.

RESULTS:
The prevalence of vitamin D insufficiency was significantly higher in the 369 patients with AITD than in the 407 without AITD (46.1% vs. 37.1%, p=0.011), and higher in the 221 patients with HT than in those with GD or non-AITD (48.9% vs. 41.9%, 37.1%, p=0.017). Among HT cases, patients with overt hypothyroidism had a significantly higher prevalence of vitamin D insufficiency (60.4% vs. 44.1%, 21.7%, 37.1%, respectively, p <0.001) and lower 25(OH)D levels (80.1 ± 47.7 vs. 99.34 ± 61.2, 110.3 ± 69.9, 99.6 ± 53.7 nmol/L, respectively, p=0.009) compared with those with euthyroidism and subclinical hypothyroidism or those without AITD. Serum 25(OH)D levels were significantly negatively correlated with serum thyroid stimulating hormone (TSH) levels after adjustment for age, sex, body mass index, and sampling season (r= -0.127, p=0.013).

CONCLUSION:
Vitamin D insufficiency was associated with AITD and HT, especially overt hypothyroidism. Low serum vitamin D levels were independently associated with high serum TSH levels.

Figure 2. The mean serum 25(OH)D levels (A) and the prevalence of vitamin D insufficiency (B) according to the presence of Hashimoto’s thyroiditis and thyroid function state in patients with

• Hashimoto’s thyroiditis. HT,
• Hashimoto’s thyroiditis; ET, euthyroidism;
• SCH, subclinical hypothyroidism;
• OH, overt hypothyroidism.

* p<0.05 vs. non-AITD, p=0.009 between groups (A), p<0.001 between groups (B).
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Vitamin D levels of Autoimmune Thyroiditis are low in winter increaase over the years - Nov 2019

Vitamin D Status and Thyroid Autoantibodies in Autoimmune Thyroiditis
Horm Metab Res. 2019 Nov 25. doi: 10.1055/a-1023-4181.
Koehler VF1,2, Filmann N3, Mann WA1.

A lack of vitamin D seems to be related to autoimmune diseases including autoimmune thyroiditis (AIT). This study intends to determine the correlation between improvement of 25-hydroxyvitamin D 25(OH)D levels and AIT in patients from an outpatient endocrine clinic in Frankfurt, Germany. This study included 933 patients with thyroid peroxidase antibodies (anti-TPO-Ab) ≥34 kIU/l, including most patients with clear AIT due to a concurrent sonographic evidence of reduced echogenicity. We performed clinical evaluation and laboratory analysis at five points in time within two years retrospectively. Due to a high dropout rate within the observation period, we excluded the last two time points from analysis. Data from 933 AIT patients revealed 89% having vitamin D deficiency or insufficiency [25(OH)D <75 nmol/l] with a median 25(OH)D level of 39.7 nmol/l. At baseline, a weak inverse correlation between 25(OH)D and anti-TPO-Ab was observed during winter (rs=-0.09, p=0.048*), but not during summer time (p>0.2).
We discovered 58 patients having initially a 25(OH)D level < 75 nmol/l (median: 40.2 nmol/l), which improved over time to a 25(OH)D level ≥ 75 nmol/l (median: 83.2 nmol/l, p<0.0005***).
Simultaneously, the median anti-TPO-Ab level showed a significant decrease of 25% from 245.8 to 181.3 kIU/l (p=0.036*). A significant reduction of the median anti-TPO-Ab level of 9% was also observed in the control group, which consisted of patients having constantly a 25(OH)D level <75 nmol/l.
The result may suggest that in particular patients with 25(OH)D levels < 75 nmol/l benefit from an increase of 25(OH)D levels ≥ 75 nmol/l. Further prospective randomized controlled clinical trials are needed to finally evaluate if vitamin D has immunmodulatory effects in AIT.

Hashimoto's thyroiditis has some assocation with poor Vitamin D Receptor - May 2021

Assocoiation amount is behind a paywall as of May 2021
Vitamin D status in Hashimoto's thyroiditis and its association with vitamin D receptor genetic variants
J Steroid Biochem Mol Biol. 2021 May 17;105922. doi: 10.1016/j.jsbmb.2021.105922
Hany William Z Hanna 1, Cristiano Rizzo 2, Radwa Marawan Abdel Halim 3, Hemmat Elewa El Haddad 4, Randa Salam 5, Hazem El-Sayed Abou-Youssef 6

Background: Hashimoto's thyroiditis (HT) is considered the predominant cause of hypothyroidism in iodine sufficient countries. The deficiency of 25-OH-vitamin D3 serum level and the variation of vitamin D receptor (VDR) gene were implicated in a number of autoimmune disorders. This study aimed to test the hypothesis linking between VDR FokI and BsmI variants and HT, in addition to explain their impact on 25-OH-vitamin D3 serum level.

Materials and methods: Cross sectional study included 160 hypothyroid subjects, 112 patients with HT and 48 hypothyroid non-HT controls. They were diagnosed based on anti-TPO Ab and or anti-TG Ab results. All cases were subjected to full history taking, thyroid ultrasound examination and a panel of assays (TSH, f.T3, f.T4, anti-TPO Ab, anti-TG Ab, calcium, alkaline phosphatase and phosphate). Serum 25-OH-vitamin D3 was assayed using HPLC-UV method. VDR variants (FokI and BsmI) were genotyped using real-time PCR.

Results: FokI AA genotype was statistically higher in HT patients than control group (P value = 0.02) with subsequently higher serum 25-OH-vitamin D3 level in comparison to all other genotypes (P value = 0.039). Serum 25-OH-vitamin D3 level was statistically indifferent between HT and control group (P value = 0.223). A statistically significant increase in total thyroid volume was observed in HT group (P value = 0.002).

Conclusion: FokI AA genotype is more associated with HT in Egyptian patients compared to hypothyroid non-HT controls. Moreover, patients with FokI AA genotype have statistically higher levels of 25-OH-vitamin D3 suggesting VDR dysfunction even in patients expressing normal level of vitamin D.

HT: Importance of Vitamin D, Iodine, Selenium, and Gluten - April 2017

A concise review of Hashimoto thyroiditis (HT) and the importance of iodine, selenium, vitamin D and gluten on the autoimmunity and dietary management of HT patients.Points that need more investigation
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See also web

• Black Seed May Treat Hypothyroidism (Hashimoto's Disease), Clinical Trial Reveals GreenMedInfo Updated Sept 2019
  1 gram a day for 8 weeks had a significant difference
• Iodine: Fuel to the Fire in Hashimoto’s GreenMed Info July 2017
  a person disagrees with consensus, believing that Iodine should be REDUCED for Hashimoto’s
  Vitamin D is NOT mentioned
• Hashimoto’s Thyroiditis: Symptoms, Causes, and Treatment SelfHacked Nov 2017
  Long article: Treatments include Vtiamin D, Iron, Selenium