Sonya, I've always believed one thing. If they are not eating or not eating enough, I will give them whatever they like and as much as they like. Calories are important. She eats a piece of bread in the morning. I put a sprinkle of vits and electrolytes in her water.
Another thing you might want to try is liver. My marek's bird goes crazy for it when I put a little raw liver in her food, nutritionally it is a super food with very high levels of B vitamins, iron, and lots of other things. I suspect it is easier to absorb the nutrients in liver than from powdered vitamins.
I am going to pick up some chicken liver today at the store and freeze it in little baggies, beef liver is about the same but with much more copper. She only eats a tiny amount however my dogs are more than happy to polish off any extra so it doesn't go to waste.
Contrary to popular belief, the liver does not store toxins, chemicals and other toxins are stored in fat.
http://chriskresser.com/natures-most-potent-superfood