Calcium Iodate and Potassium Iodide Efficacious Sources of Iodine - EFSA

Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on safety and efficacy of calcium iodate anhydrous and potassium iodide as feed additives for all animal species.



The only known role of iodine in the metabolism is its incorporation into the thyroid hormones, thyroxine and triiodothyronine as well as the precursor iodothyrosines. Both hormones have multiple functions as regulators of cell activity (energy metabolism) and growth and as transmitters of nervous stimuli and play an important role in brain development.



The use of calcium iodate anhydrous and potassium iodide as sources of iodine is considered safe for all animal species/categories when used up to the currently authorised maximum content of total iodine in complete feed, with the exception of horses, cats and dogs, for which maximum tolerated levels are 3, 6 and 4 mg I/kg complete feed, respectively.



The exposure of consumers was calculated in two scenarios applying the currently authorised maximum iodine contents in feed and reduced contents. The iodine content of food of animal origin, if produced taking account of the currently authorised maximum content of iodine in feed, would represent a substantial risk to high consumers. The risk would originate primarily from the consumption of milk and to a minor extent from consumption of eggs. The upper tolerable level (UL) for adults (600 µg/day) would be exceeded by a factor of 2, and that for toddlers (200 µg/day) by a factor of 4. If the maximum iodine concentrations in feed for dairy cows and laying hens were reduced to 2 and 3 mg I/kg feed, respectively, the exposure of adult consumers to iodine from food of animal origin would be below the UL. However, iodine intake in high-consuming toddlers would remain above the UL (1.6-fold).



In the absence of data, calcium iodate and potassium iodide are considered as irritant to the eyes, skin and respiratory tract, and as dermal sensitisers. Exposure by inhalation should be avoided.



The use of calcium iodate and potassium iodide in animal nutrition is not expected to pose a risk to the environment.



Calcium iodate and potassium iodide are efficacious sources of iodine to meet animal requirements.



The FEEDAP Panel recommends that some of the currently authorised maximum iodine contents in complete feed be modified as follows: dairy cows and minor dairy ruminants, 2 mg I/kg; laying hens, 3 mg I/kg; horses, 3 mg I/kg; cats, 6 mg I/kg and dogs, 4 mg I/kg.