Try oxbow Vit C, one a day per piggy. Mine love them. Then I can honestly say they are getting the amount they need.
That's true, but I managed to find somewhere that still had the Oxbow...so I swopped in and had them. LOL
I won't blame you if you keep it a secret ! I've stopped giving the Oxbow tablets regularly - my trio eat plenty of Vit C rich veg - but it's nice to have some in.hang on, let me check where I managed to get them from...i'll have a quick squish through my emails.