The role of the case-control study in evaluating health interventions. Vitamin supplementation and neural tube defects.
D002986:Clinical Trials as Topic / Q000379:methods; D004812:Epidemiologic Methods; D005260:Female; D005494:Folic Acid Deficiency / Q000150:complications*; D006801:Humans; D007231:Infant, Newborn; D009436:Neural Tube Defects / Q000209:etiology / Q000517:prevention & control*; D011247:Pregnancy; D011897:Random Allocation; D012306:Risk; D014815:Vitamins / Q000627:therapeutic use*
D014815:Vitamins