Originally Posted by
Kipling
vegetarians drink milk, vegans don't.
the reason it won't be suitable for vegetarians will be down to one of the following:
1: produced in a factory where cross contamination could occur, so they cannot guarantee it is not 100% suitable
2: A lot of food colourings are made using crushed insects - a good example of this would be McDonalds Strawberry Milkshakes here in the UK, for years the other 3 flavours were suitable for vegetarians, but strawberry wasn't, this is because the strawberry syrup was made using crushed insects (which is quite a common thing) - possibly the blueberry flavouring/colouring is made in a similar way?