THE EFFECT OF ORAL SELENIUM SUPPLEMENTATION ON HUMAN SPERM MOTILITY

Objectives To determine whether the decline in selenium intake and sel enium status in men in the West of Scotland might be a contributory fa ctor to male subfertility. Patients and methods Two semen samples were collected from patients attending a subfertility clinic and those pat ients with samples showing reduced motility were invited to participat e in an ethically approved double-blind clinically controlled trial wi th informed consent. Sixty-nine patients were recruited and received e ither placebo, selenium alone or selenium plus vitamins A, C and E dai ly for 3 months. A further semen sample was collected at the end of th e trial, Plasma selenium status was determined at the beginning and en d of the trial period, as was total sperm density and motility, Result s Plasma selenium concentrations were significantly (P < 0.001) higher in both selenium-treated groups than in controls. No significant effe ct of treatment on sperm density was recorded. Sperm motility increase d in both selenium-treated groups, in contrast to a slight decline in the placebo group. but the difference was not significant. However, as the provision of additional vitamins had no effect on any variable me asured it was considered justified to combine the two selenium-treated groups and compare them with the placebo treatment, On this basis, se lenium treatment significantly (P < 0.002) increased plasma selenium c oncentrations and sperm motility (P = 0.023) but sperm density was aga in unaffected. Five men (11%) achieved paternity in the treatment grou p, in contrast to none in the placebo group. Conclusion This trial con firms the result of an earlier study, that selenium supplementation in subfertile men with low selenium status can improve sperm motility an d the chance of successful conception. However, not all patients respo nded; 56% showed a positive response to treatment. The low selenium st atus of patients not supplemented again highlights the inadequate prov ision of this essential element in the Scottish diet.