AMS is a sensitive isotopic method well suited for human nutrition studies. The advantages of AMS over other current tracer methods are that small physiologically relevant dosages of the nutrient can be administered that cause radiation exposures below minimum safety thresholds, and that nutrient metabolites can be traced for prolonged periods of time, even when they have not been identified. We have used AMS to study the molecular mechanisms of several nutrients, for example the folates, tocopherols, and carotenoids. Folates are cofactors in one carbon metabolism. Folic acid supplementation appears to significantly reduce the risk of neural tube disorders and cardiovascular disease. Tocopherols are important fat-soluble antioxidants and may help prevent chronic degenerative diseases such as cardiovascular disease and cancer. Carotenoids such as ß-carotene and lutein are also antioxidants that may help prevent chronic disease, and ß-carotene is the major precursor of vitamin A and thus important for normal vision and embryonic development. We administered isotopes of folates, tocopherols, and carotenoids to healthy adult human volunteers and collected blood, urine and fecal samples for several months. After measuring nutrient and metabolite concentrations by AMS, we used the data to estimate nutrient absorption and bioavailability, and to construct kinetic models to gain insights into the metabolism of these nutrients. We report our AMS data on nutrient metabolism, and discuss the insights into nutrient metabolism that we have gained from this technique.
See more of AMS in Low Dose Bioscience Workshop
See more of The 10th International Conference on Accelerator Mass Spectrometry (September 5-10, 2005)