CSPI has filed a class action lawsuit against Glaceau VitaminWater (from the Coca-cola company) citing deceptive and unsubstantiated claims.
Coke has called the lawsuit ridiculous and ludicrous claiming that Consumers can readily see the nutrition facts panels on every bottle of Glacéau Vitaminwater, (src).
There is no doubt that VitaminWater marketers have a taste for hyperbole: bioactive components, the inside is natural, the outside is plastic. However on a serving for serving basis, it is not quite as sugary as a Coke.
VitaminWater Power-C: 13g sugar per 8oz (src)
Coke: 27g sugar per 8oz (src)
However, VitaminWater comes in 20oz bottles which equates to 32.5 grams of sugar per bottle.
The best place to get your vitamins is from food (fruit & veg), and don't expect any health miracles from drinking VitaminSugarWater.