Supreme Gerty Guinea Pig is a nutritionally balanced food suitable for guinea pigs of all ages, delicious ingredients such as maize, oats, wheat, beans and alfalfa make this a nutritionally balanced diet for guinea pigs. We add Vitamin C because it is a necessary and important component for the health of guinea pigs, since they can’t produce their own. Look out for the orange flower biscuits in the Gerty mix to know you’re feeding the right diet with the right amount of Vitamin C. Hay and water should always be freely available.