New test developed for B-12 deficiency

A safer, more accurate test for vitamin B-12 deficiency--which affects about 1,000,000 Americans over the age of 65--has been developed by researchers at the University of California, Davis.

An inability to absorb vitamin B-12 properly causes pernicious anemia, leading to fatigue and neurological complications. Yet, physicians lack a safe and simple way to test for poor vitamin B-12 absorption in their patients.

"If you can make the diagnosis, the treatment is easy and the damage can be reversed. But making the diagnosis is tricky," cautions Ralph Green, professor and chair of pathology and laboratory medicine.

The new test involves drinking a small amount of vitamin B-12 labeled with radioactive carbon 14 (14C) and collecting a single drop of blood. The amount of 14C-labeled vitamin B-12 in the sample is measured with an accelerator mass spectrometer, which can count single atoms of 14C. The radiation dose involved is equivalent to that received on a cross-country flight.

The labeled vitamin B-12 was made using a strain of Salmonella enterica bacteria. Vitamin B-12 is one of the most complex substances in nature, Green points out. Using the bacteria, the researchers had an efficient way to make the new compound for the test. They hope to license the patented technology to a company that will make the test available to physicians.

COPYRIGHT 2006 Society for the Advancement of Education
COPYRIGHT 2008 Gale, Cengage Learning