Database values do not reflect selenium contents of grain, cereals, and other foods grown or purchased in the upper Midwest of the United States

In an effort to establish reliable selenium (Se) values for foods, we have previously reported the variability of Se concentrations in foods commonly available in the upper Midwest. The present report extends this investigation to other foods as well as agricultural commodities, and has compared analyzed values to values predicted by the US Department of Agriculture National Nutrient Database for Standard Reference 16. Total variation in Se content was 72-fold (11-774 μg Se per 100 g) for wheat flakes, 57-fold (14-803 μg Se per 100 g) for wheat, and 11-fold (19-217 μg Se per 100 g) for beef. The variability between analyzed values and values found in the US Department of Agriculture National Nutrient Database for Standard Reference 16 were sufficiently large to make database values of little use for diet planning or assessment. These results emphasize that Se concentrations in foods vary, and professionals should be aware of this complication when designing diets with predicted amounts of Se.