Dairy product and dairy iodine intake among pregnant women in 2 provinces of China: A cross-sectional study

Abstract

Dairy products, a good source of iodine, have been shown to influence the iodine level of pregnant women. This study aimed to investigate the dairy iodine content, the dairy products, and dairy iodine intake of Chinese pregnant women, and related factors. A cross-sectional study included 1,013 pregnant women in Liaoning and Yunnan provinces, China. The eligible participants completed the intake records for 30 consecutive days to collect characteristics and dairy consumption. Dairy iodine intake was calculated, and the related factors were explored using the Mann-Whitney, Kruskal-Wallis H, and Jonckheere-Terpstra trend tests. An analysis compared dairy iodine intake in pregnant women to the dietary reference intakes of iodine. The iodine content of pasteurized milk (26.3 μg/100 g vs. 14.7 μg/100 g, Z = −2.335) and yogurt (21.5 μg/100 g vs. 12.6 μg/100 g, Z = −2.668) was significantly higher in Liaoning than in Yunnan province. The average dairy intake of pregnant women was 147.4 g/d, and dairy iodine intake was 31.9 μg/d. There were significant differences in dairy iodine intake by age group, province, urban or rural area, ethnicity, and education levels. The median dairy iodine intake in this study only met 12.9% to 23.4% of the estimated average requirement and 9.0% to 16.3% of the recommended nutrient intake (RNI) of local pregnant women in the 2 provinces, respectively. Consuming 500 g of dairy products provides ∼92.5 to 121.0 μg of iodine. Combined with typical iodine intake from iodized salt and other foods, this would help pregnant women meet 105% to 117% of the RNI for iodine. In conclusion, pregnant women with low levels of education, in rural areas, or from the Lahu ethnic group have a lower intake of dairy products and dairy iodine. Approximately 500 g of dairy products plus 5 g of iodized salt and other foods per day will ensure adequate iodine intake for pregnant women in areas with low water iodine.