PLASMA SELENOPROTEIN-P LEVELS OF HEALTHY-MALES IN DIFFERENT SELENIUM STATUS AFTER ORAL SUPPLEMENTATION WITH DIFFERENT FORMS OF SELENIUM

Objective: To assess changes in selenoprotein P levels in plasma from subjects who had received oral supplements of different selenium forms . Design: The same study group participated in two similar selenium su pplementation trials, Trial I in 1981 (Levander et al, 1983) and Trial II in 1987 (Alfthan et al, 1991). During Trial II the mean baseline i ntake of selenium in Finland was higher compared to that during Trial I (100 and 40 mu g/d, respectively), due to a nationwide supplementati on of fertilisers which started in 1985. Subjects: Fifty healthy Finni sh men, 35-60 y old. Intervention: The study group received daily plac ebo or oral supplements consisting of 200 mu g selenium as selenium-en riched yeast, sodium selenate or selenium-enriched wheat (Trial I) or selenium-enriched yeast, sodium selenate or sodium selenite (Trial II) . The duration of supplementation periods was 11 (Trial I) and 16 (Tri al II) weeks. Results: In Trial I the mean plasma selenoprotein P valu es in all the supplemented groups increased significantly, approaching a plateau at 2 weeks and reaching maxima at 4 weeks (mean increase 34 %, P < 0.05). In Trial II the mean selenoprotein P levels of the suppl emented groups were not significantly different from each other or fro m the placebo group at the start or at any time point of the supplemen tation period. Conclusions: At a low selenium status the selenoprotein P levels increased in a similar fashion after supplementation with di fferent forms of selenium, but at a high selenium status no significan t effects of supplementation with the same amount of selenium were obs erved. No differences in selenoprotein P levels were observed for inor ganic and organic selenium supplements. Sponsorship: This study was su pported by The Swedish Council for Forestry and Agricultural Research, the Pahlsson Foundation and the Swedish Nutrition Foundation.