The Iodine Content in Urine, Faeces and Selected Organs of Rats Fed Lettuce Biofortified with Iodine Through Foliar Application

Abstract

Iodine is an essential trace element for humans. Foliar application of micronutrients is successfully used in order to increase the concentration of essential elements in vegetables. The aim of this study was to evaluate the iodine absorption in the rat organism fed foliar biofortified lettuce. The presented study was consisted of the vegetative and animal experiment. In the vegetative experiment with lettuce, two combinations of foliar application were used: (1) control—without iodine application and (2) iodine application in the potassium iodide (KI) form. In the animal experiment, Wistar rats were divided to four groups, which received one of four diets: (1) C—control diet containing iodine in the KI form, (2) D—diet deficient in iodine, (3) D + BL—diet containing biofortified lettuce, and (4) D + CL—diet containing control lettuce (as the only source of iodine in diet, respectively). The diets contained 0.260, 0.060, 0.254 and 0.075 mg I/kg, respectively. In order to determine the iodine absorption in the rat organisms, the content of this trace element was measured in urine, faeces and in selected organs with the use of the ICP-OES technique. Foliar application of the KI increased the content of iodine in lettuce. The rats from the D + BL group excreted significantly less iodine in their urine and faeces and also accumulated more iodine in the organs than the rats from the C group. Iodine with biofortified lettuce was much bioavailable for rodents than iodine from control diet. Biofortified lettuce can be a source of iodine in a diet of human and can improve iodine nutrition.

Chemical Composition of Lettuce (Lactuca sativa L.) Biofortified with Iodine by KIO3, 5-Iodo-, and 3.5-Diiodosalicylic Acid in a Hydroponic Cultivation

“…Moreover, after KIO 3 treatment, the increase of crude fat content was noted as compared to control and other treatments. Other researchers who also studied the chemical composition of lettuce showed that the fertilization of iodine did not imply changes in nutrients content in plants [33,34].…”

Curly Kale (Brassica oleracea var. Sabellica L.) Biofortified with 5,7-Diiodo-8-quinolinol: The Influence of Heat Treatment on Iodine Level, Macronutrient Composition and Antioxidant Content

“…Pi ątkowska et al [58] reported that the concentration of iodine in the urine of rats fed a diet with raw carrot biofortified with the non-organic form of iodine (KI) during agriculture was higher compared to the urine of rats fed a diet with the control carrot. Rakoczy et al [59] also showed similar results in an animal study in which rodents were fed a diet with lettuce. But they were still lower compared to the control group where the source of iodine was a mineral mix.…”

Iodine biofortification of Swiss chard (Beta vulgaris ssp. vulgaris var. cicla) and its wild ancestor sea beet (Beta vulgaris ssp. maritima) grown hydroponically as baby leaves: effects on leaf production and quality

“…46 A study on 50 healthy volunteers, who consumed iodine-enriched potatoes, carrots, cherry tomatoes, and green salad, showed that the concentration of urinary iodine, which is the suggested indicator for determining the prevalence of IDDs, increased slightly but significantly as a result of the diet. 47 More thorough investigations on animal models demonstrated that eating biofortified carrots 48 or lettuce 49 enhanced iodine assimilation.…”