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.