These are among the questions for which we try to find answers. These neutrons are very sensitive probes that interact with individual elements in biologic monitors to both confirm their presence and quantify their content. Our knowledge of dietary requirements is considerable, but far from complete. For example, we know that in addition to carbon, hydrogen and oxygen, approximately another 20 of the 92 naturally occurring elements are required in varying amounts for good health. However, for all of these there are gaps in our knowledge concerning their detailed biological roles and the parameters that mediate those roles.
Selenium is a good example.
It was the last of the trace elements to be established as a required nutrient, in 1957. Up to that time, selenium was better known for its toxicity, which is well documented. Working with nutritional epidemiologists throughout the country, MURR life scientists have been at the forefront of the effort to unravel this and related questions regarding selenium nutrition. Continuing with this example, epidemiological trials with thousands of subjects suggest that a significant fraction of the US population may be marginally selenium-deficient, leading to an increased risk of certain cancers. At the MURR Center, we have begun to measure selenium status in Missouri's citizens, starting with an eight-county region in Central Missouri.