History and Usage: Natrol Ester-C® is a unique form of Vitamin C containing naturally occurring metabolites. Ester-C®'s patented manufacturing process neutralizes the pH, making Ester-C® gentle on the digestive system. Websites for Further Research:

http://www3.niaid.nih.gov/

http://www.webmd.com/diseases_and_conditions/...

http://en.wikipedia.org/wiki/Allergy