My child has a dental condition in which his teeth lack enamel and are hyper-subject to decay. Per his dentist, he can't drink juice, lemonade, or candy (like lollipops, skittles, fruit roll-ups) whatsoever. (The only thing he can have is chocolate because that melts immediately and doesn't cause decay.) He plays tons of sports and he likes to have Gatorade or Vitamin Water at his games, but now that's totally off-limits too. At his last dental visit, they suggested using Nuun, a tablet that you add to water to add sugar-free electrolytes.

While I hate the idea of giving him any artificial sweeteners (and mostly he will drink just water from here on in), I'd like to figure out a good solution for when he's playing sports in the heat and wants a sports drink.

Has anyone tried Nuun? Which flavors are good? Are there other good sugar-free sports drinks?