Iodine and selenium: Dietary sources and nutritional status of the population of the Kurdistan Region in Northern Iraq

Abstract

Aim

The primary aim of this study was to determine the selenium (Se) and iodine (I) food concentrations and dietary intake of the population living in the Kurdish controlled region of northern Iraq. We also assessed the extent to which iodised salt contributes to dietary iodine intake.

Methodology

Foods and samples of salt and drinking water were analysed, including 300 crops samples from 40 local farms. The results, supplemented by food composition data, were used to assess dietary Se and I intake for 410 volunteers using a semi-quantitative food questionnaire. To directly investigate the nutritional status of individuals, urine samples were also collected from participants.

Results

Selenium intake was mainly supplied by protein and cereal sources. Calculated median dietary intake of Se was 62.7 µg d⁻¹ (mean = 66.3 µg d⁻¹) with c. 72 % of participants meeting or exceeding dietary reference intake recommendations for age. Median dietary intake of I, excluding salt consumption, was 94.6 µg d⁻¹ (mean 100.2 µg d⁻¹), increasing to 607.2 µg d⁻¹ when salt (of which >90 % was iodized) was included. Salt intake was estimated to be c.13.5 g d⁻¹ (5400 mg Na d⁻¹) which greatly exceeds WHO recommended intake (< 2000 mg d⁻¹ of Na). Urine iodine concentrations indicated that 98 % of school aged children had excessive iodine intake (≥300 µg L⁻¹) and 80–90 % of all study participants had above average or excessive iodine intake (≥200 µg L⁻¹).

Conclusions

Poultry and rice are the main sources of dietary Se to this population but around a third of children receive an inadequate Se intake. Fresh fruit and vegetables are the main sources of dietary I, but consumption of local foods cannot supply adequate I without iodised salt supplementation. Consumption of iodized salt well above recommended amounts is supplying this population with substantial iodine intake. Interventions to reduce salt intake would help to limit excessive iodine intake whilst also reducing cardio-vascular risks from Na consumption.