Doctors, do you think i can buy protein shakes,fiber supplement and vitamins with food stamps?

Possibly: Each state differs some in what they allow food stamps to be used for. Fiber supplements and vitamins are likely to be allowable since they can improve and maintain overall health. Protein shakes offer benefit only in a select group of people, so unless you have documentation from a health care provider that they are indicated, food stamps may not be honored for them.