[Urinary iodine levels and dairy consumption in pre-school children in Southwest Asturias (Spain)]

Abstract

Introduction: For decades dairy products have been a major source of iodine for decades. The purpose of this study was to determine the iodine nutritional status and its relationship with dairy consumption in pre-schooler children between 2 to 5 years old in a rural area with 27,847 inhabitants.

Patients and methods: It was planned to study 200 participants, selected by random sampling, proportional to the size of the municipality, age, and sex. Parents provided urine samples to analyse urinary iodine, as well as the nutritional information through an interview. A glass of milk or a slice of cheese was considered as a ration, and a portion of other milk derivatives were considered as half rations. The nutritional status of iodine was interpreted with the median (P[percentile]₅₀) of the urinary iodine levels, and iodine intake was estimated using the mean of ration/day of milk and dairy products, fish, and eggs.

Results: Of the total of 198 subjects that took part, 193 provide urine specimens for the determination of iodine levels. The mean dairy ration/day was 3.8 (SD:1.4). More than two-thirds (69.9%) drank ≥ 2 glasses of milk/day, and 88.1% consumed a dairy ration of another dairy product. The median urinary iodine level was 184 μg/l, but was dependent on glasses of milk/day (282.5 μg/l ≥ 4 glasses) and/or the type of milk (233.0 μg/l in semi-skimmed). An intake of 115.1 μg/day to 170.2 μg/day of iodine was estimated, and that milk was the food which provided more iodine (89.9 μg/day).

Conclusions: Iodine intake was adequate, although higher than necessary when four or more glasses of milk were consumed, and/or when the milk was skimmed. The consumption of dairy products should be monitored to prevent both excessive and deficient intake of iodine.

Keywords: Child Pre-school; Iodine; Leche; Milk; Necesidades nutricionales; Nutritional requirements; Preescolar; Yodo.