The Food and Drug Administration has said it is banning the use of Red No. 3, a synthetic dye that has long been used in the U.S. to color certain foods, such as candies and colored beverages, as well as some oral medicines and supplements.

Parents say that red dye No. 3 causes behavioral issues in their kids so they avoid foods with the questionable ingredient.

Food companies have two years to get red dye No. 3 out of their products. But other synthetic dyes have also raised concerns, because of behavioral issues in kids. Here's what parents need to consider.