Bioavailability of Food Supplements

Overview

The Food Standards Agency is looking to appoint 1 supplier to deliver a systematic literature review project on ’Bioavailability of Food Supplements’ on a contracted basis from June 2026 until March 2028. Consumer use of food supplements has increased in recent years, accompanied by a growing trend for manufacturers to market novel formulations that claim enhanced oral bioavailability compared to conventional forms. These formulations include lipid-based systems such as liposomes, micelles, emulsions, and nanoparticles, as well as non-lipid approaches like particle size reduction through micronisation and co-formulation with polysaccharides. Although these products are often promoted as improving absorption, the supporting evidence remains limited and uncertain. This uncertainty is further increased by the vast variety of formulation types and the lack of data characterising their physicochemical properties. Consequently, the potential impact of these formulations on bioavailability and on toxicological risk, remains unclear and may pose concerns, particularly for under‑characterised active ingredients and vulnerable populations. The Chemical Risk Assessment Unit (CRAU), through its risk assessments and engagement with other regulators, has identified emerging risks from food supplements intake and has sought advice from the Committee on Toxicity (COT) on several actives. The lack of information on how different formulations influence the toxicological profile of active substances remains a significant data gap in the risk assessment of food supplements. Addressing this gap is critical for ensuring robust risk assessments and informed policy decisions. In their recent report on novel formulations designed to increase food supplement bioavailability, the COT recommended that novel formulations and their active agents should be assessed for toxicokinetics on a case by case basis, using model systems that account for species differences in metabolism (COT, 2025). The COT emphasised that the feeding state (fed versus fasted) is a key determinant of bioavailability and must be critically considered when comparing across formulations. Furthermore, the suitability of acceptable daily intakes (ADIs) and other health based guidance values (HBGVs) for unformulated food supplements should always be reviewed when applied to formulations designed to increase bioavailability, and approaches for relating HBGVs to differences in bioavailability should be assessed and applied on a case by case basis (COT, 2025). The work proposed in the specification contributes to the FSA Corporate Priority EG1 – Risk Analysis informed by evidence and aligns with FSA Areas of Research Interest on novel approach methods to assess chemical hazards and impact on consumers.