Historically, 400 IU (10 ug) of vitamin D was recommended for better health because it closely approximated the amount of vitamin D in a teaspoonful of cod liver oil. However, 800 to 1,000 IU is ...
In this article: Nature Made Vitamin D3 2000, Ddrops Kids Booster 600 IU ... For younger children, 10 micrograms (400 IU) is ...