title: Ethics of a randomized trial of periconceptual vitamins.
mesh_terms: D002986:Clinical Trials as Topic; D035061:Control Groups; D030881:Disclosure; D004311:Double-Blind Method; D004992:Ethics, Medical; D005260:Female; D005306:Fertilization; D006801:Humans; D038622:Internationality; D009436:Neural Tube Defects / Q000517:prevention & control; D011247:Pregnancy; D037841:Pregnant People; D011897:Random Allocation; D035842:Research Subjects; D018570:Risk Assessment; D014815:Vitamins / Q000008:administration & dosage*
chemical_list: D014815:Vitamins