New breath test to detect vitamin B12 deficiency

June 28, 2011

US research team has developed a simple, non-invasive, low-cost breath test which can more accurately measure vitamin B12 status.

The test is based on the fact that vitamin B12 plays a crucial role in the breakdown of sodium propionate (a common preservative in bakery products) into carbon dioxide. Test subjects who are given propionate will break it down and exhale carbon dioxide with the aid of vitamin B12 in the body. The amount of resulting carbon dioxide is proportional to vitamin B12 status. In order to differentiate this carbon dioxide from the gas that is exhaled in normal respiration, the propionate is labeled with a stable isotope of carbon, which is recognizable to the test instruments and measured. Individuals with vitamin B12 deficiency produce less of this type of carbon dioxide.

To confirm the accuracy of the breath test, the obtained vitamin B12 levels were compared with several blood compounds that are currently used to ascertain vitamin B12 deficiency (1). In addition, incidence of B12 deficiency was measured with the B12 breath test in 119 patients with chronic pancreatitis, Crohn’s disease, small intestine bacterial overgrowth, and subjects over 65 years of age. According to the researchers, the study results showed that the vitamin B12 breath test is a non-invasive, sensitive, specific, and reproducible diagnostic test to detect vitamin B12 deficiency. A higher incidence of B12 deficiency was, in deed, found in the test subjects.

Many publications suggest that serum B12 levels do not reflect vitamin deficiency and frequently show false positives and negative results. The new test was developed in light of the shortcomings of these vitamin B12 deficiency screening procedures. Vitamin B12 plays an important role in the functioning of the brain and nervous system. It is also essential for the formation of red blood cells. Low levels lead to fatigue, clinical depression and memory loss as well as more detrimental and irreversible effects on the brain and nervous system. Several studies have also linked vitamin B12 deficiency to pernicious anaemia and Alzheimer’s disease.

Recent research has indicated that vitamin B12 deficiency is more widespread than previously believed. A US study found that 39% of 3,000 people studied had low values. Deficiency is also known to be more common among vegetarians and vegans who do not supplement their diet. It is widespread in the developing world and in elderly populations throughout the globe.


  1. Wagner D. A. et al. A new 13C breath test to detect vitamin B12 deficiency: a prevalent and poorly diagnosed health problem. Journal of Breath Research. 2011.