Publication:

Prevalence of vitamin B12 deficiency in thyroid dysfunction and its correlation with anti-thyroid peroxidase antibodies

Background Thyroid dysfunction, particularly autoimmune thyroid disease (AITD), is linked to micronutrient deficiencies. This study assessed the prevalence of vitamin B12 deficiency in thyroid dysfunction, its levels in subclinical hypothyroidism, and its correlation with anti-thyroid peroxidase (anti-TPO) antibodies.

Methods A cross-sectional study of 124 thyroid dysfunction patients and 90 euthyroid controls was conducted. Serum TSH, free T3, free T4, anti-TPO, and vitamin B12 were measured. Statistical analyses included Chi-square tests, t-tests, ANOVA, and Pearson correlation.

Results Vitamin B12 deficiency was significantly higher in cases (29.84%) versus controls (16.67%, p=0.034). Among thyroid subtypes, overt hypothyroidism had the lowest mean B12 (151.63±45.78 pg/ml). Anti-TPO positivity was higher in cases (56.45% versus 0%, p<0.0001) and negatively correlated with B12 (r=-0.159, p=0.020). Subclinical hypothyroidism (49.20% of cases) showed intermediate B12 levels (201.86±54.45 pg/ml). Anaemia (Hb: 10.99±2.27 g/dl versus 12.70±2.88 g/dl, p<0.0001) and lower albumin (4.08±0.69 g/dl versus 4.33±0.61 g/dl, p=0.0056) were prevalent in cases.

Conclusion Vitamin B12 deficiency is common in cases with thyroid dysfunction, especially in autoimmune hypothyroidism. Routine vitamin B12 screening is recommended in these patients.