Folic acid has shown to be important in preventing birth defects. It does this in early pregnancy. It is commonly found in leafy green vegetables, peanuts, dried beans, liver, and some citrus fruits. Pregnancy also increases the body's need for iron and young women often have low levels of iron due to menstruation from before the start of their pregnancy. It is also found in potatoes, beans, and raisins.
Vegetable iron is harder to absorb.
Eating these foods in combination with others that contain vitamin C helps increase absorption. Vitamin C is in things like tomatoes, oranges and orange juice, strawberries, green pepper, broccoli, and Brussels sprouts. Caffeine decreases the absorption of iron, so try to avoid this, around meals. Also a standard multivitamin never hurts, as a back up. Sometimes this is listed as 0.4 mg.