The European Food Safety Authority's Panel on Food Additives, Flavourings, Processing Aids and Materials in Contact with Food (AFC) found no grounds for concern over Magnesium L-lysinate, calcium L-lysinate, zinc L-lysinate as sources for magnesium, calcium and zinc.
The opinion was published in reaction to a UK Health Food Manufacturers' Association (HFMA) petition to the European Commission.
"In a worst case assumption that the three lysinates would be used together in supplements as sources of respectively magnesium, calcium and zinc at the Tolerable Upper Intake levels for the cations (substances), the Panel estimated the potential exposure to lysine to be up to 353 mg/kg body weight/day for an adult with a standard body weight of 60 kg," EFSA stated.
Although this value was about double that found in normal diets, EFSA said there were no safety concerns and made reference to a rat study that demonstrated high-dose exposure to lysine with no adverse side effects.
"The Panel concluded that the use of magnesium L-lysinate, calcium L-lysinate and zinc L-lysinate used in food supplements as a source of respectively magnesium, calcium and zinc is not of safety concern at the proposed use levels."
L-Lysine is an essential amino acid salt that, following ingestion, is absorbed from the lumen of the small intestine into the enterocytes. Some metabolism of L-lysine takes place within the enterocytes and that which is not metabolised moves to the liver.
EFSA noted that exposure to the sources of 250mg a day for magnesium, 800mg a day for calcium and 15mg per day zinc, would result in consumption of anionic lysine of about 3g/day for magnesium L-lysinate, about 5.8 g/day for calcium L-lysinate and about 0.034 g/day for zinc L-lysinate.
These values are low compared to the level of lysine in protein-rich foods, EFSA noted.EFSA's opinion relates only to the lysinates as sources of magnesium, calcium and zinc and not to the mineral forms themselves. Such an evaluation was not for the AFC Panel to decide, it said.
In regard to the mineral forms in question, the AFC Panel noted:"As products containing magnesium L-lysinate, calcium L-lysinate and zinc L-lysinate are manufactured by many different companies in the EU, according to the petitioner it is difficult to obtain sales statistics to indicate the total exposure. Similarly, the total quantity of the above listed lysinates sold to manufacturers for use in food supplements in Europe is also unknown."
AFC acknowledged work done by the now defunct Scientific Committee on Food (SCF) which found tolerable upper intake levels of 250mg per day for magnesium (arrived at in 2001); 2500mg for calcium (2003) and 25mg for zinc (2003).