Detecting B12 deficiency
Armed with a $40,000 research grant, a team of researchers from UC Davis Health System and Lawrence Livermore National Laboratory is evaluating vitamin B12 absorption and metabolism in humans. The innovative approach uses micro-doses of carbon-14-labeled vitamin B12 (14C-B12) that have been synthesized by UC Davis researchers using a modified strain of bacteria.
In this pilot research study, funded by the UC Davis Clinical and Translational Sciences Center and the Department of Medical Pathology and Laboratory Medicine, individuals consume a small dose of 14C-B12 by mouth.
“The amount of radioactive exposure to the individual consuming the 14C-B12 is less than they would receive during an airplane flight,” said Joshua W. Miller, a B vitamin expert in the Department of Medical Pathology and Laboratory Medicine and principal investigator of the study. Blood, urine, and stool samples are then collected from each individual at various time points and sent to the Lawrence Livermore Laboratory, where scientists use a sophisticated instrument called an accelerator mass spectrometer to count single carbon-14 atoms.
— Joshua W. Miller, study principal investigator
“The amount of carbon-14 in the study samples tells us how much 14C-B12 is there,” he said. “We can then calculate how efficiently the person absorbed and processed the vitamin.”
According to Miller, the research has two long-term goals: to gain a basic understanding of how humans handle vitamin B12, and how potential clinical applications, particularly in assessing a person's ability to absorb vitamin B12, might be developed. The research is particularly useful to identify patients with pernicious anemia, who cannot absorb vitamin B12 and can have serious health problems, including anemia and neurological and cognitive impairment, as a result.
“Vitamin B12 deficiency is fairly common, particularly among the elderly, but is difficult to diagnose,” explained Lars Berglund, associate dean for clinical and translational research at UC Davis Health System. In the future, using the “state of the art, front-line technology” of 14C-B12 and accelerator mass spectrometry, a way of detecting vitamin B12 malabsorption, a leading cause of vitamin B12 deficiency in the elderly, may be developed.
The data generated in the pilot study by the research team will serve as the basis for future applications to the National Institutes of Health and the Food and Drug Administration to develop a diagnostic test.