One of the big challenges in selenium research is the optimizing of the daily selenium intake to reduce the risk of prostate cancer. We need more research results to answer the following questions about the use of selenium supplements to reduce the risk of prostate cancer [Waters & Chiang 2017]:
- What is the optimal formulation of the selenium supplement?
- What is the correct daily dosage?
- What is the range of baseline blood selenium concentrations that indicates a need for selenium supplementation?
- What is the blood selenium level above which selenium supplementation will not reduce the risk of prostate cancer further?
The idea that selenium intakes and selenium status are an important determinant of prostate cancer risk began to receive considerable attention after University of Arizona Professor Larry Clark published the results of the Nutritional Prevention of Cancer Trial in JAMA in December 1996 [Clark 1996].
High-Selenium Yeast Supplements in the Nutritional Prevention of Cancer Trial
The Nutritional Prevention of Cancer Trial (NPCT) was a supplementation trial using 200 micrograms of a selenized yeast preparation or placebo for an average duration of 4.5 years. The study participants were 1312 men and women with an average age 63 years.