MISCELLANEOUS INSTRUCTIONS ON VITAMIN D3 DOSE—this is a steroid hormone mistakenly named a “vitamin” in ~1922.  [Take heed:  Avoid vitamin D2, which is available by prescription only,  as 50,000 I.U. gel capsules, to be taken once a week. D2 is from plants, is less potent and has a shorter ½ life. It was grandfathered in