Iodine content of soil, white maize (Zea mays) and rice (Oryza sativa) from rural part of Anambra State, South-east Nigeria

Iodine is an essential trace element necessary for metabolism and overall health. It is unique because it is the constituent of thyroid hormones. Iodine deficiency leads to health problems known as iodine deficiency disorder (IDD).The entire landscape of Nigeria predisposes the country to iodine deficiency disorders because of its proximity to the equator and the long months of rainfall spreading from April to November. In Nigeria as well as other parts of the world, the consumption of iodized salt to improve iodine intake has been encouraged. However, locally produced salts are still found in local markets especially in our study area. Effort to improve the iodine intake of inhabitants of such areas must begin with a look at data on iodine content of local soil and locally cultivated and consumed staples. Data on iodine content of soil and food samples are relatively scarce. The aim of this study is to determine the iodine content of soil and commonly cultivated and consumed staples (rice and maize) in Ayamelum LGA of Anambra State, Nigeria. Materials and Methods- Soil samples were collected from farm land. Rice and maize samples were bought from farmers that own the farmland where soil samples were collected. The samples were prepared and analysed for iodine using alkaline dry ash method. Descriptive and correlation analysis were carried out using IBM SPSS (version 22). Results and Discussion- The results showed that mean iodine content of soil, rice and maize were 10.992±2.730µg/g, 9.110 ±0.873 µg/g and 9.083±0.857 µg/g, respectively. The iodine content of soil samples in this study was higher than the world- wide mean iodine content of soils which is 3.0µg/g. There was positive correlation between iodine content of soil samples and iodine content of the food samples (p<0.01). The sale and consumption of locally made non-iodized salt should be encouraged and enforced. Keywords: Soil, Iodine, thyroid hormone, maize, rice, iodized salt