Selenium requirements as discussed in the 1996 joint FAO/IAEA/WHO expert consultation on trace elements in human nutrition.

In March 1996, WHO officially released an updated trace element nutrition report that presents much new information, especially regarding iodine, zinc, copper and selenium. For most minerals, both basal as well as normative requirements are given. The basal requirement refers to the intake needed to prevent clinically manifest signs of impaired function attributable to deficiency of the nutrient. The normative requirement refers to the intake needed to maintain a level of tissue storage (or index enzyme activity) judged to be desirable and appropriate. In the case of selenium, the population minimum mean intakes likely to meet basal requirements for adult males and females were 21 and 16 micrograms/day, respectively. These were derived from the amount needed to protect against Keshan disease plus a body weight correction factor. On the other hand, the population minimum mean intakes likely to meet normative requirements for adult males and females were 40 and 30 micrograms/day, respectively. These were calculated from the amount needed to achieve two-thirds of the maximal plasma glutathione peroxidase activity assuming an interindividual variability of normal dietary selenium intake of 16%. Further work is needed to determine the relationship between these nutritional standards and the actual dietary intakes of selenium around the world.