Selenium is an essential trace element of importance to human biology and health. Increasing evidence suggests that this mineral plays an important role in normal growth and reproduction in animals and humans, and selenium supplementation is now recommended as part of public health policy in geographical areas with severe selenium deficiency in soil. This review addresses the biological functions of selenium followed by a detailed review of associations between selenium status and reproductive health. In many countries, selenium dietary intake falls below the recommended nutrient intakes and is inadequate to support maximal expression of the selenoenzymes. Numerous reports implicate selenium deficiency in several reproductive and obstetric complications including male and female infertility, miscarriage, preeclampsia, fetal growth restriction, preterm labor, gestational diabetes, and obstetric cholestasis. Currently, there is inadequate information from the available small intervention studies to inform public health strategies. Larger intervention trials are required to reinforce or refute a beneficial role of selenium supplementation in disorders of reproductive health.
Selenium was first discovered in 1817 by Jöns Jacob Berzelius when investigating the chemicals responsible for outbreaks of ill health among workers in a Swedish sulphuric acid plant. The local product contained a contaminant that he named Selēnē, after the Greek goddess of the moon. In 1957, Klaus Schwarz with Foltz proved that selenium is an essential nutrient necessary for both normal growth and reproduction in animals.
Selenium, amino acids, and selenoproteins
Dietary selenium, initially taken up from the soil and concentrated by plants, is absorbed in the small intestine and incorporated into proteins by complex mechanisms that remain unclear. Selenite (SeO 3 2− ; inorganic form of selenium) crosses the plasma membrane and reacts with cytoplasmic thiols in the reduction pathway; this forms selenide, which is then methylated, giving rise to methylated selenium derivatives that are excreted in urine, expired air via the lungs, and feces ( Figure 1 ) . The proportion of selenium intake excreted like this depends on dietary intakes; when this is high, urinary excretion will also be high and vice versa.
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
