I have a question about Citrulline Malate. One of my friends (who suffers from renal failure) is thinking of supplementing with a product that contains a small amount of this. I know Citrulline has something to do with Arginine in the Urea Cycle think theres something about that that relates to renal failure, but am not sure exactly how this works? Would this product be okay?
That's really something your friend needs to discuss with his/her physician. This shouldn't be a case where his/her physician (especially if a nephrologist) is completely unfamiliar with the amino acid.
Having said that, you're right citrulline is, in a way, a precursor to arginine in the urea cycle. I do know that arginine at least, has been looked at as a possible tool in certain forms of renal disease, at least in animal models, but officially, arginine is contraindicated in those with renal failure.
So, if it were me, I'd certainly avoid it, but again, this is something to be discussed with their physician.
I concur. We must not get too creative regarding self-administration / supplementation when pathologies enter the picture. Hopefully an MD will listen to sincere concerns / interests.