1) Basically 2) Crucially 3) Significantly 1) In an important way 2) To a vital degree 
• (adv.) In a vital manner.
Vi'tal·ly adverb In a vital manner. 
[adv] - to a vital degree
vitally 1. To a vital degree, or extremely important and necessary, or indispensable to the survival or continuing effectiveness of something. 2. Characterized by being required for the continuation of life.
adverb to a vital degree; `this is vitally important`