Final answer:
Metformin is a medication that affects B12 levels and requires monitoring. Other medications that may affect B12 levels include proton pump inhibitors (PPIs) and H2 blockers.
Step-by-step explanation:
The medication that affects B12 levels, necessitating monitoring, is Metformin. Metformin is commonly prescribed for the treatment of Type 2 diabetes. It has been shown to reduce B12 absorption in the intestines, which can lead to lower B12 levels in the body over time.
Other medications that may affect B12 levels include proton pump inhibitors (PPIs), such as omeprazole, and H2 blockers, such as ranitidine. These medications can interfere with the release of stomach acid, which is necessary for B12 absorption.
If you are taking any of these medications, it is important to discuss the potential impact on your B12 levels with your healthcare provider and consider regular monitoring or B12 supplementation if necessary.