The Academy of Nutrition and Dietetics: Professional national organization of registered dietitians. Source of evidence-based information for the public.

Vegetarian Dietetic Practice Group: Vegetarian practice group for dietitians through the Academy of Nutrition and Dietetics. A wealth of information is also available for the public. 

National Institutes of Health: Office of Dietary Supplements: Fact sheets covering vitamins, minerals, and a variety of other supplements.