title: Prevalence and evaluation of B12 deficiency in patients with autoimmune thyroid disease.
abstract: BACKGROUND
  Patients with autoimmune thyroid disease (AITD) have a higher prevalence of pernicious anemia compared with the general population. Clinical signs of B12 deficiency may be subtle and missed, particularly in patients with known autoimmune disease. We assessed the prevalence of vitamin B12 deficiency in patients with AITD and whether their evaluation may be simplified by measuring fasting gastrin levels.
  
  
  METHODS
  Serum B12 levels was measured in 115 patients with AITD (7 men and 108 women), with a mean age of 47 +/- 15 years. In patients with low serum B12 levels (< or =133 pmol/L), fasting serum gastrin and parietal cell antibodies (PCA) were measured.
  
  
  RESULTS
  Thirty-two patients (28%) with AITD had low B12 levels. Fasting serum gastrin was measured in 26 and was higher than normal in 8 patients. PCA were also measured in 27 patients with B12 deficiency and were positive in 8 patients. Five patients with high gastrin levels underwent gastroscopy with biopsy, and atrophic gastritis was diagnosed in all. The prevalence of pernicious anemia as assessed by high serum gastrin levels in patients with low B12 was 31%.
  
  
  CONCLUSIONS
  Patients with AITD have a high prevalence of B12 deficiency and particularly of pernicious anemia. The evaluation of B12 deficiency can be simplified by measuring fasting serum gastrin and, if elevated, referring the patient for gastroscopy.
authors.affiliation: Endocrine Unit, Sapir Medical Center, Tchernikovsky 53, Kfar Saba, Israel 44261. Rosane-Abramof.Ness@clalit.org.il
authors.forename: Rosane
authors.initials: R
authors.lastname: Ness-Abramof
authors.forename: Dan A
authors.initials: DA
authors.lastname: Nabriski
authors.forename: Lewis E
authors.initials: LE
authors.lastname: Braverman
authors.forename: Lotan
authors.initials: L
authors.lastname: Shilo
authors.forename: Eliahu
authors.initials: E
authors.lastname: Weiss
authors.forename: Tamar
authors.initials: T
authors.lastname: Reshef
authors.forename: Menachem S
authors.initials: MS
authors.lastname: Shapiro
authors.forename: Louis
authors.initials: L
authors.lastname: Shenkman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D005755:Gastrins / Q000097:blood; D006111:Graves Disease / Q000150:complications; D050031:Hashimoto Disease / Q000150:complications; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D013967:Thyroiditis, Autoimmune / Q000150:complications*; D014806:Vitamin B 12 Deficiency / Q000150:complications* / Q000175:diagnosis* / Q000453:epidemiology
chemical_list: D005755:Gastrins