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

Abstract

INTRODUCTION: Prevalence of vitamin B12 deficiency is occasionally found to be coexisting in patients with hypothyroidism causing persistence of symptoms concomitant to both diseases even on adequate thyroxine supplementation. MATERIALS: A single-centric non-interventional cross sectional study was carried over a period of 1 year. 100 hypothyroid patients were evaluated for prevalence of anemia, and investigated for the etiology. Serum Vitamin B12 was obtained and an association was studied between Vitamin B12 and anti TPO and anti Thyroglobulin antibodies. Here, vitamin B12 deficiency was defined as <160 pg/mL. RESULT: Among 100 hypothyroid patients, 31% were males and 69% were females. The mean age of patients was 36.09±12.864 years. 68% patients were found to be Vitamin B12 deficient, and 73.5% of this deficient population were females. 78.6% patients with raised Anti TPO antibodies had vitamin B12 deficiency (p-value = 0.01), while 78% patients with raised Anti Thyroglobulin antibodies were vitamin B12 deficient (p-value = 0.07). The Pearson correlation coefficient (r) was -0.302 (p = 0.002) and -0.253 (p = 0.011) between Vitamin B12 anti anti TPO and anti Thyroglobulin antibodies respectively, thus showing a negative correlation between both. CONCLUSION: Thyroid hormones affect erythropoiesis, thus causing anemia in a deficient condition. In iodine sufficient areas, most common cause of hypothyroidism is autoimmune, predisposing individuals to other autoimmune diseases, one being pernicious anemia. In the studied anemic hypothyroid population, Vitamin B12 deficiency was found correlated with raised levels of serum anti-TPO and anti-Thyroglobulin antibodies. Supplementation of B12 may alleviate hypothyroid symptoms, thus making itself a novel addition in the routine hypothyroid prescription. References Aon M, Taha S, Mahfouz K, et al. Vitamin B12 (cobalamin) deficiency in overt and subclinical primary hypothyroidism. Clin Med Insights Endocrinol Diabetes 2022;15:11795514221086634. Ness-Abramof R, Nabriski DA, Shapiro MS, et al. Prevalence and evaluation of B12 deficiency in patients with autoimmune thyroid disease. Am J Med Sci;332(3):119-122.