vitamin B↓4

例句：

1. 1.Vitamin B12 deficiency can lead to anemia.
   维生素B12缺乏可能导致贫血。
2. 2. The patient needed a blood transfusion because of his vitamin B12 deficiency.
   由于维生素B12缺乏，这位病人需要输血。
3. 3. It is important for pregnant women to consume enough vitamin B12 during pregnancy.
   孕妇在怀孕期间摄取足够的维生素B12非常重要。