The effect of selenium on phagocytosis in humans

The effect of selenium on immune responses in animals and humans is controversial. It has been reported that phagocytosis as a part of the immune function is affected by selenium deficiency. We conducted a study to investigate the effect of selenium on the phagocytic function of polymorphonuclear leukocytes (PMNs) in normal healthy individuals before and after selenium supplementation. Ingestion of sodium selenite 400 micrograms/day (182.8 micrograms pure selenium) resulted in a significant increase in plasma selenium levels. The phagocytic function of PMNs was measured by ingestion of Oil Red O paraffin droplets and chemiluminescence tests. The phagocytic function was increased, but the results before and after selenium supplementation were not significant. It was concluded that inorganic selenium was not an efficient stimulating agent of phagocytosis in humans.