title: Serum vitamin D3 levels are not associated with thyroid cancer prevalence in euthyroid subjects without autoimmune thyroid disease.
abstract: OBJECTIVE
  Previous studies have suggested that elevated serum vitamin D levels might protect against thyroid cancer. Elevated serum thyroid stimulating hormone levels and autoimmune thyroid disease (AITD) are suggested to be thyroid cancer promoting factors but have not been well controlled in previous studies. We designed the present study to evaluate whether serum vitamin D levels are associated with thyroid cancer in euthyroid patients with no clinical evidence of AITD.
  
  
  METHODS
  This cross-sectional study included subjects who underwent routine health check-ups, including serum 25-hydroxy vitamin D3 (25(OH)D3) levels, anti-thyroid peroxidase antibody (TPO-Ab), and thyroid ultrasonography (US). Inclusion criteria were euthyroid, negative TPO-Ab, and no evidence of AITD by US findings. Thyroid cancer diagnoses were based on fine needle aspiration cytology and/or postsurgical histopathological findings.
  
  
  RESULTS
  We enrolled 5,186 subjects (64% male, 37% female) in this study, including 53 patients (1%) with a diagnosis of thyroid cancer (33 males, 20 females). Mean 25(OH)D3 levels were similar between the thyroid cancer and control groups (p= 0.20). Subgroup analysis according to sex or seasonal variation also revealed no differences in 25(OH)D3 levels between the two groups. Based on the levels of 25(OH)D3, there was no significant difference in the prevalence of thyroid cancer; the prevalence was 0.71%, 0.94%, 1.40%, and 0.82% in the deficient, insufficient, sufficient, and excess groups, respectively (p= 0.64).
  
  
  CONCLUSIONS
  The levels of serum 25(OH)D3 are not associated with thyroid cancer prevalence in euthyroid subjects with no clinical evidence of AITD.
authors: Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors: Yun Mi
authors: YM
authors: Choi
authors: Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors: Won Gu
authors: WG
authors: Kim
authors: Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors: Tae Yong
authors: TY
authors: Kim
authors: Health Promotion Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors: Sung Jin
authors: SJ
authors: Bae
authors: Health Promotion Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors: Hong-Kyu
authors: HK
authors: Kim
authors: Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors: Eun Kyung
authors: EK
authors: Jang
authors: Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors: Min Ji
authors: MJ
authors: Jeon
authors: Department of Internal Medicine, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, Korea.
authors: Ji Min
authors: JM
authors: Han
authors: Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors: Young Kee
authors: YK
authors: Shong
authors: Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors: Won Bae
authors: WB
authors: Kim
mesh_terms: D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000097:blood; D015415:Biomarkers / Q000097:blood; D044963:Biopsy, Fine-Needle; D002112:Calcifediol / Q000097:blood*; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors; D012621:Seasons; D066106:Seoul / Q000453:epidemiology; D013963:Thyroid Hormones / Q000097:blood; D013964:Thyroid Neoplasms / Q000097:blood* / Q000000981:diagnostic imaging / Q000453:epidemiology*; D013997:Time Factors; D014463:Ultrasonography; D014808:Vitamin D Deficiency / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology*
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; D013963:Thyroid Hormones; C056626:thyroid microsomal antibodies; D002112:Calcifediol
keywords: Thyroid autoimmunity; Thyroid neoplasms; Vitamin D