Which vitamin is essential for enterocyte health?

• A. Vitamin B12
• B. Vitamin A
• C. Vitamin D
• D. Vitamin K

Answer: (A)

Enterocytes are constantly renewing cells lining the small intestine, so their health hinges on proper DNA synthesis and cell division. Vitamin B12 plays a central role in one-carbon metabolism that supports DNA synthesis and methylation reactions required for rapid enterocyte proliferation. Specifically, B12 enables the methionine synthase reaction and helps folate-dependent pathways supply thymidine for DNA replication. When B12 is sufficient, enterocytes can divide and mature normally, maintaining a healthy, intact mucosal layer and efficient absorption. In contrast, deficiency impairs DNA synthesis in these rapidly renewing cells, leading to mucosal thinning and compromised barrier function. So, vitamin B12 is essential for maintaining enterocyte health through its support of enterocyte renewal and intestinal mucosal integrity.