My favorite is a mixture of oats, wheat bran, and clovite.
I mix the oats and the wheat bran together and then 7 parts that mixture to one part Clovite.
Chinchillas get 1/2 teaspoon a few times a week.
All of these ingredients come from the local farm feed store.
Clovite is a vitamin powder that contains:
Soybean meal, Soy flour, Vitamin A & D oil, Dicalcium phosphate, Vitamin B12 supplement, Vitamin A & D3 supplement, Choline chloride, Vitamin E supplement, Calcium pantothenate, Niacin, Pyridoxine hydrochloride, Thiamine hydrochloride, Riboflavin, Biotin.