It is always best to be careful. There are so many products out there to choose from, you don't need to risk it.
I found personally that even some that say they are gluten free can still make me sick. For instance, some products claim to be certified gluten free because they have less than 20 ppm of gluten present in the product. Hey, people, there is still gluten, just not very much. Eat this in large quantities, or a little bit everyday, and it will add up! (I learned this one the hard way, you know stomach cramps, fatigue, weight loss, etc.)
If you are unsure, you can always call the manufacturer! You know they hear stuff like this all the time, and actually may have a gluten statement already ready for you on their website!
Remember, we are following this diet to improve our health. We don't have to, we choose to. We want to improve the quality of our life so we can be there for our families and friends when they need us. When you focus on why you are doing it, it helps make the 'what to eat' decisions a lot easier.
Have a Healthy, Happy, Gluten Free Day!