There has been accumulation of the nutritional muscular dystrophy of the cattle in a certain western district of Finland where the prevalence of multiple sclerosis (MS) is also highest. This animal disease is due to lack of selenium (Se) and vitamin E. The Se content of whole blood was low (52.6 +/- 11.3 ng/ml) in MS patients from this high-risk area compared to the controls (68.8 +/- 11.0). The data for serum failed to confirm this tendency. All Se values appeared to be lower than international values suggested. The values for both vitamin E and copper were within the international normal range.