Comparative standards are reference values from reputable and authoritative sources such as government agencies, independent scientific panels, standards organizations, and scientific and professional organizations. These include population-based growth charts, nutrient intake recommendations and laboratory norms, as well as disorder-specific guidelines.

For comparison of nutrient intake to established standards of the Dietary Reference Intakes (DRI) see: https://www.nal.usda.gov/sites/default/files/fnic_uploads//energy_full_report.pdf.

For PROP-specific nutrient intake recommendations and evidence refer to the Nutrition Recommendations section, Question 1: Nutrient Intakes.