The FDA approes of 200 IU for 19-50 year olds; 400 IU for people oer 50. Most itamin pills contain 400 IU of itamin D.是什么意思_The FDA approes of 200 IU for 19-50 year olds; 400 IU for people oer 50. Most itamin pills contain 400 IU of itamin D.在线翻译_英语_读音_用法_例句