Vitamin C is necessary for your guinea pig's health, but like humans, your cute fuzzball cannot produce the vitamin itself. Guinea pigs depend entirely on their diet to maintain their vitamin C levels. How can you make sure your guinea pig is getting enough vitamin C?
Hay is an essential part of the guinea pig diet, but it does not contain much vitamin C. Fresh vegetables, on the other hand, are a great source of the vitamin. Dandelion petals, chicory, beetroot, rosehip, parsley and paprika in particular contain high concentrations of vitamin C. The same applies to broccoli and other cabbages, but these can lead to flatulence. Fruits such as banana or kiwi are also allowed, but they are packed with sugar. As such, dispense vitamin C from these sources in moderation!
Only give your guinea pig dry food that is specifically intended for the animal. This is enriched with extra vitamin C. Replace food every day, because vitamin C evaporates quickly when it comes into contact with air. For the same reason, close the packaging well once you have fed your critters.