Cicchini Claudia, De Magistris Antonio, Del Sasso Alberto, Livoli Donatella, Pugliese Francesco Rocco
Emergency Department, Sandro Pertini Hospital, Rome, Italy.
Eur J Case Rep Intern Med. 2025 May 9;12(6):005398. doi: 10.12890/2025_005398. eCollection 2025.
Vitamin B12 deficiency is characterised by haematological and neurological complications, from mild symptoms (e.g. fatigue and paraesthesia), to severe symptoms (e.g. pancytopenia and combined degeneration of the spinal cord). If treatment is delayed, irreversible neurological damage may occur. Thus, early recognition and prompt corrective therapy are essential. The vitamin B12 deficiency can be due to a variety of anomalies: the paradoxical interaction between folic acid and vitamin B12 has recently been well described.
We report the case of a patient who presented to the emergency department with balance disorders and a blood count indicating macrocytosis. Vitamin B12 deficiency and a high folate value were detected, supporting the hypothesis of the high-folate-low-vitamin B12 interaction as a cause of vitamin B12 depletion.
An excessive oral intake of folic acid leads to a reduction in the active fraction of vitamin B12 and this decrease exacerbates the deficiency itself. The neurological signs and symptoms of vitamin B12 deficiency are due to demyelination of the posterior and lateral columns of the spinal cord. This patient had been taking folic acid for 30 years and the serum folate value was high. We hypothesise that the high-folate-low-vitamin B12 interaction represents the cause of vitamin B12 depletion in this patient.
All the patients with neurological signs and symptoms should be tested for possible vitamin B12 deficiency: early diagnosis and treatment could stop the progression of the disease and allow the regression of the neurological deficit. It is important not to rely on blood count values to diagnose a vitamin B12 deficiency as the neurological and haematological outlook may be inversely proportional. This study is the first to report a case of combined sclerosis and high-folate-low-vitamin B12 interaction from Italy and is therefore of interest to public health decision makers and clinical practice.
Vitamin B12 and folate should be measured in all patients with neurological symptoms.In case of vitamin B12 deficiency, folate levels should always be measured as well.Vitamin blood levels should be checked periodically while taking vitamin supplements.
维生素B12缺乏症的特征是血液学和神经学并发症，症状从轻到重不等，包括轻微症状（如疲劳和感觉异常）到严重症状（如全血细胞减少和脊髓联合变性）。如果治疗延迟，可能会发生不可逆的神经损伤。因此，早期识别和及时的纠正治疗至关重要。维生素B12缺乏可能由多种异常情况引起：叶酸与维生素B12之间的矛盾相互作用最近已得到充分描述。
我们报告了一名患者的病例，该患者因平衡障碍到急诊科就诊，血常规显示大细胞性贫血。检测到维生素B12缺乏且叶酸值高，支持高叶酸-低维生素B12相互作用是维生素B12耗竭原因的假说。
过量口服叶酸会导致维生素B12的活性部分减少，这种减少会加剧维生素B12缺乏本身。维生素B12缺乏的神经体征和症状是由于脊髓后柱和侧柱脱髓鞘所致。该患者服用叶酸已有30年，血清叶酸值很高。我们推测高叶酸-低维生素B12相互作用是该患者维生素B12耗竭的原因。
所有有神经体征和症状的患者都应检测是否可能存在维生素B12缺乏：早期诊断和治疗可以阻止疾病进展，并使神经功能缺损得以恢复。重要的是，不能仅依靠血常规值来诊断维生素B12缺乏，因为神经学和血液学表现可能成反比。本研究是首次从意大利报告一例合并硬化症与高叶酸-低维生素B12相互作用的病例，因此对公共卫生决策者和临床实践具有参考价值。
所有有神经症状的患者都应检测维生素B12和叶酸。如果存在维生素B12缺乏，也应始终检测叶酸水平。服用维生素补充剂时应定期检查维生素血水平。
