Neural Tube Defects (NTDs) are one of the most severe congenital malformations. A study was conducted to determine whether supplementation with folic acid or a mixture of seven other vitamins (A, D, B1, B2, B6, C, and nicotinamide) around the time of conception could prevent neural tube defects. A total of 1817 women at high risk of having a pregnancy with a neural tube defect (because of a previous affected pregnancy) were allocated at random to one of four groups: 1) folic acid; 2) other vitamins; 3) both; 4) neither. 1195 had a completed pregnancy; 27 of these had a known neural tube defect, 6 in the folic acid groups and 21 in the two other groups. This resulted in a risk ratio= 0.28. Based on the results of the study, which of the following is an appropriate conclusion? a)There is no difference in the effect of folic acid on NTDs b) None of these c) Folic acid increases risk of NTDs d) Folic acid is protective against NTDs

Neural Tube Defects (NTDs) are one of the most severe congenital malformations. A study was conducted to determine whether supplementation with folic acid or a mixture of seven other vitamins (A, D, B1, B2, B6, C, and nicotinamide) around the time of conception could prevent neural tube defects. A total of 1817 women at high risk of having a pregnancy with a neural tube defect (because of a previous affected pregnancy) were allocated at random to one of four groups: 1) folic acid; 2) other vitamins; 3) both; 4) neither. 1195 had a completed pregnancy; 27 of these had a known neural tube defect, 6 in the folic acid groups and 21 in the two other groups. This resulted in a risk ratio= 0.28. Based on the results of the study, which of the following is an appropriate conclusion? a)There is no difference in the effect of folic acid on NTDs b) None of these c) Folic acid increases risk of NTDs d) Folic acid is protective against NTDs