Would it be a good idea to take a multivitamin daily along with a whey protein shake?

Good for the Sellers: Vitamins, small molecules so common in essentially all food such that humans have not maintained every gene/protein-enzyme to construct them out of other molecules (typically missing just 1 step) once discovered were cheap to recover from otherwise food waste & have become a huge market for products to sell. The issue: is taking extra a benefit &, if so, what is the benefit; yet too much is toxic.

No problem: Most normal diets in the usa need no vitamin supplementation. On the other hand, many many people take them. The only harm is likely to be in the thickness of your wallet or the length of your credit card bill. My advice to patients is to take anything you feel would benefit you as long as you are positive it will not hurt you. A multivitamin will not hurt you.