Does anyone know, or can you guide me to how many people hold an MD, JD, and MBA together simultaneously?

I would think that there would be no way to find this out accurately because it would be based on statistics based upon gathered information. And, for people to know this, they would have to gather enormous amounts of information from all over the world.

Why do you need to know, please?

You might also want to rephrase your question. It looks like, to me, that you want to know how many people hold the degrees of MD, JD, and MBA as being different people simultaneously. Or, how many people hold all of these degrees for themselves as an individual.