As of 2015, a list of foods containing niacin can be found at the Dieticians of Canada, Orgeon State University and The World's Healthiest Foods. The World's Healthiest Foods displays the amount in each serving, in milligrams and as a percent of the daily recommended intake.
Protein-rich foods tend to have higher levels of niacin because of their tryptophan content, which the human body converts to niacin. Fruit and vegetables do not contain as much niacin, with only portabello mushrooms and the potato listed by the Dietitians of Canada.
The World's Healthiest Foods ranks each food with an overall health rating. Food rankings are determined by, nutrient density, cost, availability, taste, environmental impact and level of processing.