Effects of vitamin D on thyroid autoimmunity markers in Hashimoto’s thyroiditis: systematic review and meta-analysis
What this study found
Vitamin D supplementation reduced thyroid autoantibody titres in Hashimoto’s thyroiditis. TPOAb and TGAb titres decreased. Effects were greater with vitamin D3 and longer treatment duration (>3 months). TPOAb: overall reduction (SMD −1.11; 95% CI −1.92 to −0.29; P=0.008); duration >3 months (SMD −1.66; 95% CI −2.91 to −0.41; P=0.009); vitamin D3 specifically (SMD −1.48; 95% CI −2.53 to −0.42; P=0.006). TGAb: reduction (SMD −1.12; 95% CI −1.96 to −0.28; P=0.009). Authors’ conclusion: vitamin D may reduce autoantibody titres in HT, especially with vitamin D3 and longer treatment; more robust…
- Study & population
- Eight randomized controlled trials in adults with Hashimoto’s thyroiditis (HT); total participants 652 (intervention 332; control 320); ages generally mid-30s to mid-40s; predominantly female; some participants on levothyroxine (LT4) therapy; study designs were randomized controlled trials, with several double-blind and placebo-controlled arms; conducted…
- Intervention
- Calcitriol (1,25-dihydroxyvitamin D3): 25 mg once daily for up to 24 weeks.
- Key limitation
- Significant heterogeneity across trials; relatively small number of studies; some trials included LT4 co-treatment; most studies conducted in China; variability in vitamin D regimens; potential publication bias and short follow-up.
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Open PDFOriginal abstract
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.