Dietary Iodine Intake in Urban and Rural North India: Implications for and Compatibility with Salt Reduction Efforts

The World Health Organization (WHO) recommends reducing dietary salt intake to < 5g/d as a cost-effective strategy to reduce hypertension and associated cardiovascular diseases. However, salt is also used as a vehicle for iodine supplementation for preventing iodine deficiency disorders. Concerns have been expressed that reducing population salt intake will adversely impact iodine levels.

The aim of this paper was to estimate the daily salt and iodine consumption levels of the adult population in India and examine the effect of the WHO-recommended salt intake levels on iodine levels.

A cross-sectional study was conducted in Delhi and Haryana, India, among adults aged ≥20 y, and 24-h urine samples were collected to assess the salt and iodine levels.

The mean salt intake was 8.07 g/d (95% confidence interval: 7.03, 9.11), median urinary iodine concentration (UIC) was 167.8 μg/L (102.63-284.5), and the mean urinary iodine excretion (UIE) was 276.1 μg/ 24h (254.5-297.8). Analysis to assess iodine intake adequacy by salt intake levels indicated that the median UIC, as well as UIE, were adequate when salt intake was as per the WHO-recommended level, i.e., ≤5 g/d.

Even at the WHO-recommended salt intake levels, population iodine intake in this study population was adequate, likely indicating that upward titration in iodine concentration in salt may not be required. Thus, current salt reduction recommendations are unlikely to impact iodine supplementation efforts, indicating compatibility between the 2 interventions, which should be continuously monitored through robust surveillance.