Guinea pigs, primates and humans do NOT produce vitamin C in their bodies, so they MUST get it from their diet. If they do not consume adequate amounts of vitamin C they will suffer from a deficiency called scurvy.
Signs of scurvy include lethargy, diarrhoea, weight loss, and internal skeletal-muscular haemorrhage.

Vitamin C is also a water-soluble vitamin, so it can not be stored in the body. These animals therefore need to get vit C in their diet every day.

Wild guinea pigs eat a variety of plant matter – and plants contain high levels of vitamin C.

If you want more detail consider this:

In the wild guinea pigs are grazers – they eat all the time. Their diet is low in calories, so they must eat a large quantity to get enough energy. It is easy to get enough vit C when you eat such a large amount of fresh food! Many pet guinea pigs are fed a complete diet, with very little fresh food. As a result you need to get all the requierd vit C in a much smaller quantity of food.

Please visit this site for more info:

http://www.guinealynx.com/scurvy.html
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The answer is same as the first person. The grasses and greens they eat provides them with the vitamin c they need.
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Yes, they can’t produce it for themselves, but they don’t need anymore than any other animal does.

I think that somehow people relate not being able to make it or store it means they somehow need mega doses of it. That’s not true.

They are tiny little animals. They need tiny doses of Vitamin C.

This is a question of evolution and survival of the fittest. If they weren’t getting the vitamins they need, they wouldn’t be able to live and breed. Because they are, they get enough vitamins.
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