Due to the non-specificity of symptoms and possibly severe consequences of untreated vitamin B-12 deficiency, screening is important for at-risk patients to ensure the prompt delivery of treatment. In this review, studies assessing the prevalence of vitamin B-12 deficiency in thyroid dysfunction are evaluated to determine whether regular vitamin B-12 screening is necessary. A literature search was conducted using multiple electronic databases. Only original studies assessing the prevalence of vitamin B-12 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 B-12 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 B-12 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 B-12. Vitamin B-12 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.
由于维生素B-12 缺乏症状没有特异性以及不治疗可能引起严重的后果,筛选 出有风险的患者以确保及时治疗非常重要。本综述评估了甲状腺功能紊乱患者 中维生素B-12 缺乏症的患病率,以确定定期筛查维生素B-12 是否必要。在多 个电子数据库中进行文献检索。只有在甲状腺功能紊乱患者中评估维生素缺乏 症的患病率、并报告了患病率的原始研究才纳入分析。全部查到的7091 篇文 献中,有6 篇纳入本综述。三个独立的研究报告甲状腺机能减退患者中维生素 B-12 缺乏的发生率分别为10%、18.6%和40.5%。三个研究报告自身免疫性甲 状腺疾病维生素B-12 的缺乏率分别为6.3%、28%和55.5%。甲状腺功能减退 和自身免疫性甲状腺疾病患者中维生素B-12 的缺乏反映了该人群的营养状 况。自身免疫性甲状腺疾病也与自身免疫性疾病恶性贫血和萎缩性胃炎有关, 而恶性贫血和萎缩性胃炎又可能导致维生素B-12 吸收不良。建议在初次诊断 自身免疫性甲状腺疾病时筛查维生素B-12,之后定期检查维生素B-12。没有 足够的证据建议在甲状腺功能减退患者中需定期筛查维生素B-12,除非甲状腺 功能减退的根本原因是自身免疫性疾病。.