EFSA’s Scientific Panel on Food Additives and Nutrient Sources added to Food (ANS) also commented on the bioavailability of copper from copper oxide.
Although kidney effects have been demonstrated in male rats at levels as low as 10 mg/kg body weight/day and a human study showed gastrointestinal disturbances, the ANS concluded that, “provided that the Tolerable Upper Intake Level is not exceeded, the use of copper(II) oxide as a source of copper at the proposed use levels is not of safety concern.”
Copper, found in liver, nuts, sunflower seeds and oysters, is important for the brain, blood flow and bones.
The ANS found that overall exposure from all food sources was in the range of 3.6-4.7 mg/day for adults and 3.7-6.7mg/day at the 97.5th percentile. For children the mean copper exposure was 3.4-3.6mg/day and 4.1-4.9 mg/day at the 97.5th percentile assuming children take the adult dose of the supplement.
It noted Reported No-Observed-Adverse-Effect-Levels in the range of 23-104mg/kg, bw/day for copper.
The approval means the nutrient can be added to the positive list of the 2002 Food Supplements Directive (FSD).
Dossiers were submitted by the UK Heath Food Manufacturers Association; Béres Pharmaceuticals Ltd; Kabco Pharmaceutical Ltd and the Danish Food and Veterinary Administration.
Further detail
The petitioners applied for copper oxide to be used in food supplements at levels of 2mg copper/day for adults, which is equivalent to 2.5mg of copper(II) oxide.
One of the petitioners noted products with 2.5mg copper, corresponding to 3mg copper(II) were present on-market.
RFSA’s predecessor, the Scientific Committee on Food (SCF) established a Population Reference Intake (PRI) of 1.1mg copper/day in 1993. But a level for copper oxide had not been reached until now.
Regarding efficaciousness, the ANS noted: “Copper(II) oxide shows lower bioavailability compared to other inorganic sources of copper(II) due to its low solubility. However, the Panel notes that copper from copper(II) oxide is expected to be bioavailable to some extent.”
The opinion can be found here.