Expanded approach to tolerable upper intake guidelines for nutrients and bioactive substances.

Area of Science:

• Nutritional Science
• Toxicology
• Risk Assessment

Background:

• The tolerable upper intake level (UL) method for nutrient safety is limited as it only applies when high intakes cause harm.
• Absence of a UL is often misinterpreted, leading to restrictive policies for nutrients lacking established hazards.
• Existing methods may not adequately address nutrients without identified adverse effects from high consumption.

Purpose of the Study:

• To introduce and define the observed safe level (OSL) as an alternative to the UL for nutrient safety assessment.
• To address the limitations of the UL method, particularly for nutrients without established hazards.
• To propose a more robust risk assessment technique for nutrient safety, incorporating the highest observed intake (HOI).

Main Methods:

• The observed safe level (OSL) is defined as the highest intake with convincing evidence of safety.
• The highest observed intake (HOI) concept, similar to OSL, was recently defined by FAO/WHO.
• An alternative uncertainty factor (UF) approach involves data evaluation from highest to lowest intake, selecting data with no observed adverse effects and sufficient quality.

Main Results:

• The OSL method provides a highest intake level with convincing evidence of safety, irrespective of established adverse effects.
• The OSL-HOI technique can be applied to nutrients, bioactive substances, and amino acids where adverse effects are not clearly established.
• This method allows for risk assessment values even when traditional UL criteria are not met, using robust datasets.

Conclusions:

• The OSL-HOI technique offers a more nuanced and applicable approach to nutrient risk assessment than the traditional UL.
• This method prevents misinterpretation of data for nutrients lacking established hazards, avoiding overly restrictive policies.
• Application of the OSL-HOI technique can provide valuable risk assessment data for a wider range of substances.