"Nutrition Information" is correct. In this case "Nutrition" is a noun adjunct, meaning a noun has been used as an adjective. This is very common in English. For example, say "chicken soup" instead of "soup of chicken".
In fact, nearly any noun can be an adjective.
- If you are going to a show about cars, you can call it a "car show".
- If you refer to the slide on a trombone, call it a "trombone slide".
- A device used to open cans is a "can opener".