Final answer:
Vitamin C (Ascorbic Acid) is not specifically beneficial for pregnancy outcomes when taken before pregnancy, unlike folic acid, iron supplements, and omega-3 fatty acids, which are known to support healthy pregnancy and fetal development.
Step-by-step explanation:
The substance among the options provided that is NOT beneficial for pregnancy outcomes when taken before pregnancy is Vitamin C (Ascorbic Acid). Substances like folic acid, iron supplements, and omega-3 fatty acids are known to be crucial for a healthy pregnancy and fetal development. Folic acid is particularly important for preventing neural tube defects and is recommended in increased amounts before and during pregnancy.
Iron helps prevent anemia in the mother and is important for the baby's growth and brain development. Omega-3 fatty acids are important for the baby's brain and eye development. However, while Vitamin C is important for general health, it is not specifically associated with improved pregnancy outcomes when taken before pregnancy.