A Study on Vitamin B12 Levels in Hypothyroid Patients Presenting to a Tertiary Care Teaching Hospital

Background and aims The prevalence of vitamin B12 deficiency is found to coexist in hypothyroid patients, causing the persistence of symptoms concomitant to both diseases even on adequate thyroxine supplementation. Primary objective To study vitamin B12 levels in patients with hypothyroidism. Secondary objective To study the clinical profile of patients with hypothyroidism with special reference to anemia, and to study the association between vitamin B12 deficiency with anti-thyroid peroxidase (anti-TPO) antibodies and anti-thyroglobulin (anti-Tg) antibodies in patients with hypothyroidism. Methods and results A single-centric cross-sectional study was carried out over a period of one year. Among 100 hypothyroid patients, 68% were found to be vitamin B12 deficient, among whom 73.5% were females. Of patients with raised anti-TPO antibodies, 78.6% had vitamin B12 deficiency (p = 0.01), while 78% of patients with raised anti-Tg antibodies were vitamin B12 deficient (p = 0.07). The Pearson correlation coefficient (r) of vitamin B12 with anti-TPO and anti-Tg antibodies was -0.302 (p = 0.002) and -0.253 (p = 0.011), respectively. Conclusion There is a predilection of hypothyroid patients toward developing anemia, with vitamin B12 deficiency as a major etiology. This finding can be correlated with the hematopoietic action of thyroid-stimulating hormones as well as autoimmune thyroid disease predisposing to pernicious anemia.