Vitamin B12: Test Overview

content provided by Healthwise

Test Overview

A vitamin B₁₂ test measures the amount of vitamin B₁₂ in the blood. The body needs this B vitamin to make blood cells and to maintain a healthy nervous system.

Vitamin B₁₂ is found in animal products such as meat, shellfish, milk, cheese, and eggs. Most people who eat animal products are not likely to develop vitamin B₁₂ deficiency anemia. unless their bodies cannot absorb it from food. Vitamin B₁₂ is stored in the liver for a year or more, which reduces a person's risk of anemia. Strict vegetarians (vegans) who do not eat animal products, and babies of mothers who are strict vegetarians are at increased risk for developing anemia and should take a supplement containing vitamin B₁₂.

Vitamin B₁₂ is usually measured at the same time as a folic acid test, because a lack of either one can lead to a form of anemia called megaloblastic anemia. Lack of vitamin B₁₂ also affects the nervous system.

E-mail This | Print This Previous Chapter | Next Chapter

Last updated:	February 14, 2007
Author:	Jan Nissl, RN, BS
Reviewed By:	Kathleen Romito, MD - Family Medicine, Brian Leber, MDCM, FRCPC - Hematology
Editors:	Susan Van Houten, RN, BSN, MBA, Tracy Landauer