A combination of fresh vegetables with high vitamin C content, together with high quality guinea pig pellets containing stabilized vitamin C, is sufficient for most guinea pigs.
Guinea pigs need vitamin C because, unlike most other animals, they aren't able to make it themselves. A great way to ensure your guinea pig receives enough vitamin C is to feed it fresh vegetables that have a high vitamin C content, such as kale and mustard greens, bell peppers, carrots, and broccoli. Providing guinea pig pellets and timothy hay also helps your guinea pig achieve the daily recommended amount of this vitamin (about 25 mg). You can also provide vitamin C chewable tablets as a treat or crushed and sprinkled on the food to further ensure your guinea pig is getting enough.
Because vitamin C is water soluble, it can be added to water, but the taste may be unpalatable for some animals. In addition, it loses potency rather quickly and needs to be added every day. In addition, some veterinarians are concerned that adding vitamin C to the water will decrease water intake of the guinea pig and potentially increase the guinea pig's risk of urinary stones.
