I would concur with Dr. Wakshlag.
It would be very difficult to get enough vitamins and minerals in her with the products that the holistic vet wants to use.
Choline is in the vitamin B family.
It should be in her diet but does not replace Denosyl or Vetri DMG as far as I know.
I think most homecookers want to use whole foods to get vit/min into their dogs but it just is impossible to meet all their needs like that. I just gave into the vit supplement because it is healthier in the long-run then to have Ellie undersupplemented. Since all foods have a different make-up, you would have to constantly change things around to get the perfect mix into her. I had also read that it would take 43 apples with peelings a day for a medium dog to get all of just one type of vitamin (forgot what one it is now). I am thinking about changing to human vitamins (we would have about 100 bottles sitting around if I went this way) but right now I use an all-in-one called Balance IT K. It is made for liver issues and is complete and balanced. You would add nothing, no choline, no iodine, etc. It is made for dogs though and I'm not sure about the safety of the ingredients.
From what I gather from Ellie's nutritionist, the vegetables are added last, shouldn't make up more than 50% of the diet because they can dilute the nutrients and are more filling than nutrient-rich.
I think after your nutritonist has balanced the diet, it might be okay to add some to the diet yourself or just ask him to add some in... It is good fiber anyway.