Department of Pediatrics, Military Teaching Hospital Mohammed V, Faculty of Medicine and Pharmacy, University Mohammed V, Rabat, Morocco.
Department of Pediatrics, Children's Hospital, Faculty of Medicine and Pharmacy, University Mohammed V, Rabat, Morocco.
Pan Afr Med J. 2021 Mar 4;38:237. doi: 10.11604/pamj.2021.38.237.20967. eCollection 2021.
Vitamin B12 deficiency in early childhood is an important cause of neurodevelopmental delay and regression. Most of these cases occur in exclusively breast-fed infants of deficient mothers. Symptoms and signs of vitamin B12 deficiency appear between the ages of 2 to 12 months and include vomiting, lethargy, failure to thrive, hypotonia, and arrest or regression of developmental skills. Approximately one half of this cases exhibit abnormal movements, variously described as tremors, twitches, chorea, or myoclonus. Urinary concentrations of methylmalonic acid and homocysteine are characteristically elevated in vitamin B12 deficiency. Hyperglycinuria is sometimes present. The early diagnosis and treatment of vitamin B12 deficiency is crucial for significant neurological impairment and long-term prognosis. Treatment with vitamin B12 corrects these metabolic abnormalities very rapidly (within a few days). Vitamin B12 supplementation of pregnant women may prevent neurological and neuroradiological findings of the infants. Because of the importance of vitamin B12 in the development of the foetal and neonatal brain, vegetarian and vegan mothers should be aware of the severe and not fully-reversible damages caused by insufficient nutritional intake of vitamin B12 during pregnancy and lactation. Therefore, efforts should be directed to prevent its deficiency in pregnant and breastfeeding women on vegan diets and their infants. It is also important to take the nutritional history of both infants and their mothers for the early prevention and treatment. Here an interesting case of vitamin B12 deficiency in a 10-month-old boy presented with psychomotor regression, hypotonia and lethargy.
儿童早期维生素 B12 缺乏是神经发育迟缓及倒退的重要原因。这些病例大多发生在维生素 B12 缺乏的纯母乳喂养的母亲的婴儿中。维生素 B12 缺乏的症状和体征出现在 2 至 12 个月之间，包括呕吐、嗜睡、生长不良、低张力和发育技能停滞或倒退。大约一半的病例出现异常运动，各种描述为震颤、抽搐、舞蹈病或肌阵挛。维生素 B12 缺乏症患者的尿甲基丙二酸和同型半胱氨酸浓度明显升高。有时存在高甘氨酸尿症。维生素 B12 缺乏症的早期诊断和治疗对于显著的神经损伤和长期预后至关重要。用维生素 B12 治疗可迅速纠正这些代谢异常（在几天内）。孕妇补充维生素 B12 可预防婴儿的神经和神经放射学发现。由于维生素 B12 在胎儿和新生儿大脑发育中的重要性，素食和纯素母亲应该意识到在怀孕期间和哺乳期内，由于营养摄入不足而导致的严重且不完全可逆的维生素 B12 缺乏症的危害。因此，应该努力预防素食孕妇和哺乳期妇女及其婴儿的维生素 B12 缺乏症。了解婴儿及其母亲的营养史对于早期预防和治疗也很重要。这里介绍了一例 10 个月大男孩维生素 B12 缺乏症的有趣病例，表现为精神运动倒退、低张力和嗜睡。
