Dietary opinions vary widely among the Sugar glider community. However, I can say this: Always feed fresh fruits and veggies. Do your research on what vitamins are essential and should be fed in larger quantities as well as what fruits and veggies should NOT be eaten. Always be feeding fresh fruits and veggies to your sugar gliders every day. Mine often get whatever treats we are eating throughout the day if we can spare them. I know some vitamin powders need to be fed every other day. ALWAYS READ INSTRUCTIONS.
I would say to research the diets. Research the foods if you supplement with any. I supplement with Exotic Nutrition's food on top of my other foods I give my gliders.
I don't think that will harm your gliders, fresh fruits and veggies are EXACTLY what they need. Added vitamins from stores are there to supplement and add more to their diets.
Hope that helps!