Iodine Concentration in Milk, Ricotta Cheese, and Yogurt, and Their Contribution to Dietary Iodine Intake

Iodine deficiency is the leading preventable cause of neurological damage worldwide. Dairy foods represent an important dietary iodine source. This study aimed to assess iodine concentration in milk, ricotta cheese, and yogurt, and to evaluate their contribution toward the recommended daily iodine intake. Whole pasteurized milk (WM; n = 12), partially skimmed pasteurized milk (PM; n = 21), skimmed pasteurized milk (SM; n = 7), ricotta cheese (RC; n = 26), whole yogurt (WY; n = 13), and low-fat yogurt (LY; n = 15) were purchased in local stores. Samples were analyzed through inductively coupled plasma mass spectrometry for iodine quantification. After removing outliers, the final dataset comprised 11 WM, 19 PM, 7 SM, 26 RC, 13 WY and 15 LY samples. Data were investigated through a mixed model with iodine concentration as the dependent variable, product type as fixed effect, and brand as random effect. Low-fat yogurt exhibited the greatest estimated iodine concentration (293.76 µg/kg), while SM and WM exhibited the lowest (211.92 and 197.63 µg/kg, respectively). Based on these results, a serving of milk (250 g) would provide 31.82–39.08% of the average daily iodine requirement, a serving of ricotta (125 g) 21.66%, and a yogurt jar (125 g) 21.54–24.11%. These findings confirm the nutritional relevance of dairy products as primary iodine sources.