HEALTH TOPICS 
By the way, doctor: Should I stop taking these vitamins?
Q. In addition to a multivitamin, I have been taking vitamin B12 supplements (1,000 mcg) for a few years, hoping to increase my energy. My recent blood profile showed a high level of B12 (1,826 pg/ml). Should I stop taking B12? My energy is about the same.
A. Severe B12 deficiency usually occurs with a condition called pernicious anemia, an uncommon disorder that arises from the inability to absorb the vitamin from food because the stomach does not make enough intrinsic factor, a protein that facilitates B12 absorption.
To continue reading this article, you must log in.
Subscribe to Harvard Health Online for immediate access to health news and information from Harvard Medical School.
- Research health conditions
- Check your symptoms
- Prepare for a doctor's visit or test
- Find the best treatments and procedures for you
- Explore options for better nutrition and exercise
New subscriptions to Harvard Health Online are temporarily unavailable. Click the button below to learn about our other subscription offers.