Comparing Nutritional Fact Panels

We have typically compared our nutrition fact panels at the 1/4 tsp (.5g) serving size. A colleague has been pushing that we need to make all of the comparisons at 100g instead. An example of why this is important is this. We set our nutrition panel for one specific onion powder and then onion powder is bought from a new supplier and they have different sodium levels. They may be out of the acceptable range at the 100g level, but when looked at from the serving size, they both report as 0%. Where is the documentation that I can use to determine the best way to compare nutritional values, ensure compliance, and not be perceived as misleading our customers?

I'm sure you've seen this FDA guidance, if not, hopefully it's of some help