If i have lupus should i stay away from vitamins since its an immune system thing?

No: In spite of "pop" wisdom, vitamins don't really enhance / overactive immunity in people who are otherwise adequately nourished. You might benefit from a b-complex with c or a good multivitamin with minerals because of the extra challenges your body faces.

No: There is no reason to stay away from them but there is also little reason to take them.