<prompt> When should folic acid supplementation start in order to be effective in preventing neural tube defects?As soon as pregnancy is diagnosedBefore the beginning of 2nd trimesterAt least one month before conceptionAt least 1 week before conception  <response>: Ans. C. At least one month before conception To be effective, folic acid supplementation should be started at least 1 month before conception, and continued through the first 2-3 months of pregnancy. All women desirous of becoming pregnant should consume 400-800mg folic acid daily; the dose is 4mgday in those having delivered a child with neural tube defect. 