The organization and daily routine of a wagon train depended on the danger expected from the Native American tribes into whose territory it had traveled, the terrain, and the size of the caravan. Mormon trains, in particular, had a semi military formation.
Side effects. Taken at normal doses, selenium does not usually have side effects. An overdose of selenium may cause bad breath, fever, and nausea, as well as liver, kidney and heart problems and other symptoms. At high enough levels, selenium could cause death.
Although selenium is clearly important for optimal synthesis of thyroid hormones, and the thyroid gland normally stores both iodine and selenium, there is little scientific evidence from well-designed studies to suggest that selenium supplementation has sustained beneficial effects on thyroid function.