Statement of EFSA on the safety of calcium L-ascorbate with a content of threonate produced by a new manufacturing process as a source of vitamin C in food supplements
Following a request from the European Commission, EFSA was asked to evaluate if calcium L-ascorbate with a content of threonate produced by a new manufacturing process and resulting in the by-product 4-hydroxy-5-methyl-3(2H)-furanone (4-HMF), was covered by the EFSA Opinion adopted in 2007 on “Calcium L-ascorbate with a content of threonate for use as a source of vitamin C in food supplements”. The biological and toxicological data available were insufficient for the safety evaluation of calcium L-ascorbate with a content of threonate, containing 4-HMF as an impurity. However, EFSA’s CEF Panel has previously evaluated 4-HMF within a group of five related α,β-unsaturated 3(2)-furanones and concluded that the related 4-hydroxy-2,5-dimethylfuran-3(2H)-one
(HDMF) could be considered as the representative compound for this group for read-across purposes. HDMF did not show carcinogenic potential in a 2-year carcinogenicity study performed according to OECD and GLP. This study gave a NOAEL of 200 mg HDMF/kg bw/day. Using a worst case estimated intake of 4-HMF of 12.9 µg/kg bw/day based on a maximum residue of 0.06% (w/w) in the final product the margin of safety (MOS) in relation to the NOAEL of 200 mg/kg bw/day for HDMF would be 15,000. EFSA concluded that this MOS is large enough to cover intra- and interspecies differences as well as uncertainties from the read across approach and exposure to 4-HMF and related α,β-unsaturated 3(2)-furanones from other dietary sources. Based on these considerations EFSA concluded that the residual level of 4-HMF in calcium L-ascorbate with a content of threonate is unlikely to be of safety concern. Therefore, the safety of the proposed uses of the source produced by the new production process can be considered as covered by the existing EFSA Opinion on ‘Calcium ascorbate with a content of threonate for use as a source of vitamin C in food supplements’.