Food allergy mom. Are you pregnant or nursing? If you are, you need to get adequate nutrition despite your food allergies, or the answer could be yes. If you aren't sure you are getting enough nutrients, ask your obstetrician or pediatrician to refer you to a registered dietician. They will help you get the right nutrients to have a healthy baby. If all else fails, there are supplemental Amino Acid drinks to take.
Unlikely. I suppose it depends on what you are allergic to and whether or not you are able to eat a well balanced diet, rich in fruits and vegetables despite your food allergies.