On a liquid diet, what vitamins/minerals are key to not deprive my body from what it needs to be healthy and able to excercise?

All of them!: By definition all vitamins are necessary for good health, as well as all essential minerals, essential Amino Acids ; essential fatty acids. Without details it's impossible to know what nutrients your liquid diet is providing. Consider a good-quality multivitamin (see http://bit.Ly/1b36cq0 ) or a protein powder with vitamins ; minerals (such as k*pax protein blend or thorne mediclear. See comment:.