- 期刊
- Ahead-of-Print
Prevalence of Vitamin B12 Deficiency Among Patients with Thyroid Dysfunction
並列摘要
Due to the non-specificity of symptoms and possibly severe consequences of untreated vitamin B12 deficiency, screening is important for at-risk patients to ensure the prompt delivery of treatment. In this review, studies assessing the prevalence of vitamin B12 deficiency in thyroid dysfunction are evaluated to determine whether regular vitamin B12 screening is necessary. A literature search was conducted using multiple electronic databases. Only original studies assessing the prevalence of vitamin B12 deficiency in thyroid dysfunction that reported their findings as percentages of the sample were eligible for inclusion. From a total of 7091 manuscripts generated, 6 were included in this review. The prevalence of vitamin B12 deficiency in hypothyroidism was reported as 10, 18.6, and 40.5% in three separate studies. The prevalence of deficiency in autoimmune thyroid disease was reported as 6.3, 28, and 55.5% in three studies. The prevalence of vitamin B12 deficiency in hypothyroidism and autoimmune thyroid disease are reflective of the nutrition status of the population. Autoimmune thyroid disease is also associated with the autoimmune disorders pernicious anemia and atrophic gastritis which may lead to malabsorption of vitamin B12. Vitamin B12 screening is recommended upon initial diagnosis with autoimmune thyroid disease and then periodically thereafter. There is not enough evidence to recommend regular screening for patients with hypothyroidism unless the underlying cause is autoimmune thyroid disease.