What are sulfites?
Sulfites are a group of preservatives commonly used in dried fruit and products containing dried fruit, wine and other beverages, flavored vinegars (for example, balsamic vinegar), and many salad dressings. Sulfites are a common allergen and can cause headaches, bowel irritability, behavioral problems, skin rashes, and other symptoms. They are particularly dangerous for asthmatic individuals, who can develop bronchospasm (a sudden constriction of the airways) after eating foods or drinking wine preserved with sulfur dioxide or other sulfites. Sulfites destroy thiamine (vitamin B1) and might destroy folic acid (vitamin B9) in the foods to which they're added.
On food labels, they may be listed as sodium sulfite, sulfur dioxide, sodium or potassium bisulfite, sodium metabisulfite or potassium metabisulfite.
Dean D. Metcalfe, Ronald A. Simon, Food allergy: adverse reactions to food and food additives, Wiley-Blackwell 2003, pp 324-339.
Medical Management Guidelines for Sulfur Dioxide. Agency for Toxic Substances & Disease Registry. 2008. Retrieved from http://www.atsdr.cdc.gov/mhmi/mmg116.html.