Scientific Opinion on the safety and efficacy of Lenziaren (iron, aqua carbonate hydroxyl oxo starch sucrose complex) as a feed additive for cats

Lenziaren, Fe(III) starch–saccharose complex, other zootechnical additives, cats, phosphorus absorption, safety, efficacy
First published in the EFSA Journal
3 May 2013
16 April 2013
Scientific Opinion


The additive Lenziaren is a polynuclear Fe(III) starch/saccharose complex intended to be used in food for adult cats to reduce phosphate absorption in the gastrointestinal tract in order to prevent chronic kidney disease. The recommended minimum and maximum levels are 0.25 g and 1.0 g per cat per day, equivalent to 5 000 and 20 000 mg/kg feed, respectively. The FEEDAP Panel considers that Lenziaren is safe for adult cats at the maximum recommended dose. However, the consequences of chronic exposure have not been investigated. The additive is not genotoxic. No adverse effects were seen in a repeat-dose toxicity study in mice. Lenziaren had no adverse effects on reproduction and development at dose levels that were not toxic to the mother. A no observed adverse effect level (NOAEL) of 500 mg/kg body weight (bw) per day was identified for Lenziaren on the basis of maternal toxicity (diarrhoea and reduced body weight gain), which was seen in rabbits at an oral dose of 1 000 mg/kg bw per day or greater. Similar effects were seen in rats, dogs and monkeys at higher doses in repeat-dose toxicity studies. No NOAELs were identified in these studies. Lenziaren is not regarded as an irritant to skin or eyes or as a skin sensitiser. Although some inhalation exposure is possible, it is not expected to be harmful to those exposed as a result of handling the additive. Based on the results of three in vivo efficacy studies, the FEEDAP Panel concludes that Lenziaren has the potential to be efficacious in cats at the highest recommended dose of 1 g/cat per day (equivalent to 20 000 mg/kg feed). However, the FEEDAP Panel has some reservations regarding the value of its long-term use in healthy cats. The Panel concludes that there is a need for a post-market monitoring plan.

Panel members at the time of adoption

Gabriele Aquilina, Alex Bach, Vasileios Bampidis, Maria De Lourdes Bastos, Lucio Guido Costa, Gerhard Flachowsky, Mikolaj Antoni Gralak, Christer Hogstrand, Lubomir Leng, Secundino López-Puente, Giovanna Martelli, Baltasar Mayo, Fernando Ramos, Derek Renshaw, Guido Rychen, Maria Saarela, Kristen Sejrsen, Patrick Van Beelen, Robert John Wallace and Johannes Westendorf
Panel on Additives and Products or Substances used in Animal Feed
EFSA Journal 2013;11(5):3204
Question Number
On request from
European Commission
The full opinion will be published in accordance with article 8(6) of Regulation (EC) No 1831/2003 once the decision on confidentiality, in line with article 18(2) of the Regulation, will be received from the European Commission.