vitamin B↓{12}c

例句：

1. 1.Vitamin B12 deficiency can lead to serious health problems.
   维生素B12缺乏可能导致严重的健康问题。
2. 2.The elderly should take extra vitamin B12 supplements to prevent anemia.
   老年人应该服用额外的维生素B12补充剂以防止贫血。
3. 3.A diet rich in vitamin B12 is essential for good health.
   富含维生素B12的饮食对健康至关重要。