The body cannot make its own supplies of B12 yet without an adequate dietary supply from animal sources or enriched cereals people can suffer anaemia, risk nerve damage and even death. Vitamin B12 deficiency can go undetected for several years, remaining invisible to doctors while the likelihood of irreversible cell damage increases.
The new process picks up early warning signs of a deficiency in the vitamin by differentiating between the active and inactive components. It tracks concentrations of holo-transcobalamin, a biologically active complex of the vitamin plus a carrier protein.
Although the holotc complex carries only 20 per cent of the body's vitamin B12, the other 80 per cent is not nearly as significant since it is effectively not available for uptake by the cells, say developers of the test, Norwegian diagnostics company Axis Shield.
But current diagnostic techniques only measure the total amount of B12 in the blood. Because these tests do not discriminate between holotc and the inactive vitamin, they can misleadingly return a healthy result for patients with too little active B12.
Lars Orning, Axis Shield project manager, said: "Current methods are technically good, but have low diagnostic sensitivity. The HOLOTC test isolates vitamin B12, enabling early identification of patients with B12 malabsorption."
Axis Shield, currently working on a simple, automated, adaptable radio immunoassay to begin clinical testing, is expecting to take a leading share of the world market for vitamin B12 diagnostic tests with the new test.
Denmark's University of Aarhus, which provided research capabilities, will benefit from royalties and sales of essential test materials.
Naturally occurring forms of B12 are found predominantly in meat and dairy products, while a synthetic form, called cyanocobalamin, is used to fortify foods and to make dietary supplements. Research shows that high doses of B vitamins can reduce levels of the amino acid homocysteine, linked by scientists to risk for Alzheimer's disease and the onset of heart disease. The vitamin may also help people to fight depression andthere is evidence of its role in bone health.