Ethylenediamine dihydroiodide (EDDI) is a water-soluble salt derived from ethylenediamine and hydroiodic acid. It is a colorless to light yellow crystalline powder. The salt consists of the ethylenediammonium dication C<sub>2</sub>H<sub>4</sub>(NH<sub>3</sub>)<sub>2</sub><sup>2+</sup> and iodide anions.
EDDI is used as an additive in pet food and cattle feed with high bioavailability. Used to prevent iodine deficiency, this salt is one of the major uses of the element iodine. The United States Food and Drug Administration suggests a limit of intake to 50 mg/head/day. Although EDDI is generally recognized as safe (GRAS) only as a nutrient source of iodine, administration of EDDI also has preventative effects on foot rot in cattle.
Other iodine supplements for animal feed include calcium iodate (most stable) and potassium iodide.
Calcium iodates are another source of nutritional iodide.