FOOD FACTS TO ALL MOTHERS of Green-Ration-Book Children Every time you see your child's green ration book think of cod liver oil and orange juice! That will help you to remember to get them from the welfare clinic, Food Office or distributing centre, and remind you to give them to your child each day. WHY does the healthiest child need cod liver oil and orange juice? (a) Cod liver oil increases a child's resistance to infections, helps to build strong bones and good teeth. It also helps to prevent rickets.