title: Vitamin D supplementation reduces thyroid peroxidase antibody levels in patients with autoimmune thyroid disease: An open-labeled randomized controlled trial.
abstract: OBJECTIVE
  Although Vitamin D deficiency has been linked to autoimmune thyroid disorders (AITD), the impact of Vitamin D supplementation on thyroid autoimmunity is not known. This study aimed to evaluate the impact of Vitamin D supplementation on thyroid autoimmunity (thyroid peroxidase antibody [TPO-Ab] titers) in patients with newly diagnosed AITD in a randomized controlled trial.
  
  
  METHODS
  One hundred two patients with newly diagnosed AITD (TPO-Ab > 34 kIU/L and/or sonographic evidence of thyroiditis) patients were randomized into Group-1 (intervention group) and Group-2 (control group). Group-1 received cholecalciferol 60,000 IU weekly and calcium 500 mg/day for 8 weeks; Group-2 received calcium 500 mg/day for 8 weeks. Responders were defined as ≥25% fall in TPO-Ab titers. Individuals with at least 3-month follow-up were analyzed. Trial is registered at ctri.nic.in (CTRI/2015/04/005713).
  
  
  RESULTS
  Data from 100 AITD patients (68 with thyroid stimulating hormone [TSH] ≤10 mIU/L, 32 with TSH > 10 mIU/L), 93% having Vitamin D insufficiency, were analyzed. TPO-Ab titers were highest among patients in the lowest 25-hydroxyvitamin D quartile (P = 0.084). At 3 months follow-up, there was significant fall in TPO-Ab in Group-1 (-46.73%) as compared to Group-2 (-16.6%) (P = 0.028). Sixty-eight percentage patients in Group-1 were responders compared to 44% in Group-2 (P = 0.015). Kaplan-Meier analysis revealed significantly higher response rate in Group-1 (P = 0.012). Significantly greater reduction in TPO-Ab titers was observed in AITD with TSH ≤ 10 mIU/L compared to TSH > 10 mIU/L. Cox regression revealed Group-1 followed by TPO-Ab and free tetraiodothyronine levels to be a good predictor of response to therapy (P = 0.042, 0.069, and 0.074, respectively).
  
  
  CONCLUSIONS
  Vitamin D supplementation in AITD may have a beneficial effect on autoimmunity as evidence by significant reductions in TPO-Ab titers.
authors.affiliation: Department of Endocrinology and Metabolism, Institute of Post Graduate Medical Education and Research and Seth Sukhlal Karnani Memorial Hospital, Kolkata, West Bengal, India.
authors.forename: Sandeep
authors.initials: S
authors.lastname: Chaudhary
authors.affiliation: Department of Endocrinology, Post Graduate Institute of Medical Education and Research, Dr. Ram Manohar Lohia Hospital, New Delhi, India.
authors.forename: Deep
authors.initials: D
authors.lastname: Dutta
authors.affiliation: Department of Endocrinology and Metabolism, Institute of Post Graduate Medical Education and Research and Seth Sukhlal Karnani Memorial Hospital, Kolkata, West Bengal, India.
authors.forename: Manoj
authors.initials: M
authors.lastname: Kumar
authors.affiliation: Department of Radiology, Institute of Post Graduate Medical Education and Research and Seth Sukhlal Karnani Memorial Hospital, Kolkata, West Bengal, India.
authors.forename: Sudipta
authors.initials: S
authors.lastname: Saha
authors.affiliation: Department of Biochemistry, Dr. B C Roy Post Graduate Institute of Basic Medical Education and Research, Institute of Post Graduate Medical Education and Research and Seth Sukhlal Karnani Memorial Hospital, Kolkata, West Bengal, India.
authors.forename: Samim Ali
authors.initials: SA
authors.lastname: Mondal
authors.affiliation: Department of Endocrinology and Metabolism, Institute of Post Graduate Medical Education and Research and Seth Sukhlal Karnani Memorial Hospital, Kolkata, West Bengal, India.
authors.forename: Ashok
authors.initials: A
authors.lastname: Kumar
authors.affiliation: Department of Endocrinology and Metabolism, Institute of Post Graduate Medical Education and Research and Seth Sukhlal Karnani Memorial Hospital, Kolkata, West Bengal, India.
authors.forename: Satinath
authors.initials: S
authors.lastname: Mukhopadhyay
keywords: Autoimmune hypothyroidism; Vitamin D; autoimmunity; thyroid peroxidase antibody; thyroiditis