Yes, children and toddlers can take Selenium. The daily recommended dietary allowances (RDAs) of selenium are: -children 1-3 years, 20 mcg; -children 4-8 years, 30 mcg; -children 9-13 years, 40 mcg. The tolerable upper limit is: -infants up to age 6 months, 45 mcg per day; -infants 7 to 12 months, 60 mcg per day; -children 1 to 3 years, 90 mcg per day; -children 4 to 8 years, 150 mcg per day; -children 9 to 13 years, 280 mcg per day.