At one time human beings could only satiate their thirst with water. In the past ten thousand years, however, some other beverages have arisen that have challenged water as our main thirst quencher, and currently there are beverages out there for sale that mention "water" in their title. Of course just mentioning water in advertising makes us think of the satisfaction of having our thirst quenched, but are these beverages really worth it? I was asked to talk about Vitamin Water Zero specifically, so let's see what this can and can't do for us.
Side note: For an entertaining and informative view regarding how man-made beverages have influenced and been used in the history of the human race, I highly recommend the Book A History of the World in Six Glasses by Tom Standage.
First of all, one of the things I didn't realize was there was more than one variety of Vitamin Water Zero, but a quick trip to their website indicates that there are 5 different varieties and soon to be a sixth. And one of the other things I've noticed is that the labels can be a little confusing at first. For example, let's take a look at the label for Vitamin Water Zero Go-Go. First note the serving size and servings per bottle--the serving size is 8 oz, and there are 2.5 servings per bottle (20 oz bottle). (In my experience--and it is my experience, I haven't conducted a true study!--people drink the whole bottle over the course of a day or a much shorter period of time!) Now look at the carb content, which is four grams per serving, or ten grams for the whole bottle. Normally carbohydrates contain 4 calories per gram, so if there's four grams of carb per serving, there should actually be about 16 calories per serving and about 40 calories per bottle. Why the discrepancy? The answer lies in looking at the ingredients. One of the ingredients is erythritol, which is a a special type of carbohydrate called a sugar alcohol. Sugar alcohols typically only contain about two calories per gram of carbohydrate, but erythritol is even more unique in that is contains only 0.24 calories per gram, and labeling regulations in the US say that this can count as zero calories. If you really wanted to do the math correctly, you are actually getting 2.4 calories for the whole bottle, but considering a twelve ounce can of regular Coke would give you about 140 calories, I'm not going to be terribly worried about the calorie content. Eyrthritol appears to be safe also, so I am not worried about that either. I am worried, however, about people drinking things without reading all the ingredients or learning more about said ingredients!
As far as the vitamin supplementation that one can get through these products, I covered the pros/cons of supplementation in this post. Unless you are known to be deficient in something, supplementation won't help you. If you already make a point of eating a variety of vegetables, some fruit, and a variety of protein sources, you are going to get all the vitamin C, B-vitamins, etc that your body needs to function and the little bit of extra isn't going to give you extra energy, or fight off a cold, or basically do anything it subtly or not so subtly claims it does.
Now, there are some people who just like the taste of something other than plain water. At that point I just remind people that it's their money and they can spend it how they want, but they might want to try plain sparkling water with lemon, lime, peppermint oil, etc for something that's a little cheaper. I have also had some elderly patients with dementia who have developed a dislike for water for whatever reason, and using the sugar free flavored waters actually helped them want to drink more.
Take home message--don't expect to get anything other than expensive urine from Vitamin Water Zero.