If you have anxiety should u avoid certain vitamins?

No: no- unless you are allergic to certain vitamins.

Not aware of any: specific vitamins that should be avoided but use caution before using supplements because some may ^ anxiety.

Some supplements: Too much of anything, even vitamins can be bad. Vitamins are no substitute for a poor diet. Caffeine will make you jittery as I am sure you know. Some supplements may have some side effects that you don't like. Read the ingredients and check online first at trustworthy sites (things that end in .edt, .org, and .gov) Also wikipedia gives pros and cons and can be quite good on supplements.