Iodine Concentration in Iranian Dairy Milk Products and Its Contribution to the Consumer’s Iodine Intake

BACKGROUND:Due to the large proportion of iodine present in milk and dairy products, they have been one of the important sources of nutritional iodine in several countries. Information about variation in milk iodine concentration in Iran is limited. OBJECTIVES:The present study was conducted to determine the iodine concentration in Iranian milk and dairy milk products. METHODS: In the first step, 10 commercial dairy farms (five located in tropical and other located in cold region) were included in the study. In the second step, the iodine concentration of six samples of different milk products from the retail market was determined by Sandell-Kolthoff (acid-digestion) reaction. RESULTS: The average iodine concentration of milk samples from cold region was significantly lower (50.7 ± 24.3 %) than the iodine concentration of milk samples from the tropical region (P<0.05). Sterilized milk (282.0 ± 111.0 µg/l) had higher and raw milk (224.3 ± 116.9 µg/l) had lower iodine concentration  (P<0.05). There was no effect of milk fat class (whole and semi-skimmed) on milk iodine concentration (P>0.05). CONCLUSIONS: Based on Iranian dairy product intake, raw, pasteurized and sterilized milk provides on average, 74.6, 84.6, 96.0 µg of iodine, approximately 29.8, 33.8, 37.6 % of the adult recommended dietary allowance for this nutrient, respectively.