Hi
yes, specific supplements help whether or not there are allergies....they just work best when any allergens are also eliminated
many people with TS seem to have chemical sensitivity so avoiding both artificial additives to foods as well as environmental chemicals can be very helpful. We immediately notice the effect of chemicals when my son either ingests them or goes into an environment where chemicals are used (including lawn garden and indoor and also chlorine in the pool)
here is an article on things that can trigger tics
http://www.latitudes.org/articles/finding_triggers.htm
hope that helps