A new faster method to measure quantities of vitamin B12, both in foods and in dietary supplements has been developed by scientists at the US government's Agricultural Research Service.
A microbiological assay is commonly used to analyse the amount of B12 in samples. But researchers say that this method can take days, is expensive and while it measures the total amount of B12 in a sample, it does not show how much of each of the individual forms of vitamin B is present.
The newer method for quantifying cobalamins, the family name for B12, uses one of two separation techniques, capillary electrophoresis (CE) or micro-high-performance liquid chromatography (HPLC), combined with a detection technique called inductively coupled plasma mass spectrometry (ICP-MS).
This hybrid method is designed to allow scientists to quickly detect and measure levels of specific cobalamins, according to Nancy Miller-Ihli, head of the trace element lab in the Food Composition Laboratory at the ARS Beltsville Human Nutrition Research Center in Maryland.
The ARS lab is now testing various food and supplement samples using CE-ICP-MS to measure the different cobalamins. Preliminary results report important data findings in commercial vitamin supplements. Future projects will focus on human breast milk, said ARS.
Vitamin B12 is an essential nutrient linked to human growth and cell development. Naturally occurring forms are found predominantly in meat and dairy products, while a synthetic form, called cyanocobalamin, is used in the United States 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.
Accuracy in measuring the quantity of each of the cobalamins in foods and supplements is crucial for understanding absorption mechanisms, which will lead to health recommendations important to the public.