CRN backs RDA approach to nutrient level setting

Recommended Dietary Allowances (RDAs) provide the best model for guiding proposed rule-making in regard to Daily Values, according to the Council for Responsible Nutrition.

The Washington DC-based trade group said in a letter to the Food and Drug Administration (FDA) that RDAs were "the only logical basis" for DVs because they were based on optimal nutrition and wouldn't leave segments of the population facing nutrient deficiencies if more conservative models were followed.

Despite this, the trade group recommended lower levels for several nutrients including vitamin D, B6, niacin and zinc than existing DVs.

"Use of an RDA (or Adequate Intake)-based and population-coverage approach, not a population-weighted average for DVs on the food label will provide the best available targets for nutrient intake and ensure consistency with other nutrition policy initiatives (such as the USDA Dietary Guidelines for Americans and the Food Guide Pyramid)," it said in its letter authored by its senior vice president of scientific and international affairs John Hathcock, PhD and scientific and regulatory affairs director Andrew Shao, PhD. Hathcock and Shao pointed out the Estimated Average Requirement (EAR) as one model that would lower the DV for many nutrients by establishing values at the lower end of acceptable intakes that would meet only portions of the population's needs.

They said levels should be based on the nutrient requirements of the most needy sections of the population so that all were covered and poured scorn on the idea that overdosing on certain nutrients was becoming more prevalent.

They highlighted iron as a nutrient at which EAR levels, if adopted, could have a devastating effect on public health.

"For iron, with many consumers using the DV as surrogates for their specific RDA, a population-weighted EAR as the basis of the DV for iron could produce adverse decreases in the iron intake of young women," the wrote.

CRN said AIs should be used for those nutrients that had no established RDA and warned against a system that borrowed from both models.

"In the absence of RDAs, AIs should be used as the basis of the DV.

A regulation that bases some DVs on EARs and others on AIs would make no sense by using target intakes for some nutrients and average requirements for others.

Further, doing so would be confusing and misleading to consumers and health professionals."

It added: "The reasons and rationale are identical to those presented above in the EAR-RDA discussion.

The need is for population-coverage values because many consumers use label values as their individual target intakes."

CRN also made special mention of dietary fiber of which it said, "the FDA should not limit the definition of dietary fiber to include certain fiber types."