The CRN called for safety values for dietary supplements to be harmonised and urged that upper levels for supplements (ULS) be "based on science not politics".
"Safety assessments of vitamins and minerals in supplements must be based on a scientific evaluation," said John Hathcock, vice president of scientific and international affairs for the CRN, and the author of Vitamin and Mineral Safety.
He explained that he wanted to see quantitative methods of risk assessment and an evaluation of potential adverse effects of nutrients looking at dose sizes.
"While the use of a Recommended Dietary Allowance (RDA) or arbitrary multiples of RDAs to set upper limits for vitamin and mineral supplements has been seen by some governments as convenient, they have no scientific validity and consequently should have no role in determining safety or upper limits," he added.
Mark Mansour, CRN's legal counselor supported this view, saying governmental and regulatory organizations worldwide need to look more closely at how to evaluate the safety of vitamins and minerals.
"The implications of some countries accepting science as the rational approach to safety, while others choose less rigorous methods lead to undesirable consequences for industry and for consumers," said Mansour, particularly in a world with fewer trade boundaries, where consumer choice needs to be protected.
While Anette Dickinson, CRN president, acknowledged the importance of safety from a consumer point of view, she drew attention to the fact the safety margin for vitamins and minerals is quite wide.
"Consumers need to pay attention to the nutrients they are getting through conventional foods and dietary supplements, but we know they are more likely to fall short in essential nutrient intake than they are to take excessive amounts," said Dickinson.
"While more is not always better when it comes to vitamins and minerals, generous intakes are usually better than low intakes," she said.
Hathcock demonstrates the breadth of these safety margins in Vitamin and Mineral Safety. Aimed at supplement marketers and regulators, the book provides a review of safety levels for 28 vitamins and minerals, as well as details on CRN's methodology for assessing safety and a review of the approaches adopted by governmental and regulatory organizations.
This latest edition provides updated recommendations based on recent science, therefore recommending higher safety values for four nutrients, lower safety values for five nutrients and adding three newly-evaluated nutrients. In addition, the second edition focuses on identifying safety values for supplemental quantities of nutrients, rather than total intakes from all sources.