I recently learned that elderberry extract is good for immunity support, but I am worry about the affects that it will have on my 2 1/2 yo sons glucose levels and wondering if it will spike his levels.  I really want to keep him from getting every bug out there.  It is combo with agave nectar which i just discovered has a low GI.  Please give me any advise regarding this issue and if anyone has any experience with natural immunity boosters.