Iodine – Uses, Benefits, Sources and Dosage Iodine is natural occurring nutrient in the body which plays important role in body. It is important for growth and development. It is essential for the regulation of thyroid hormone which plays role in basic metabolic rate. Importance of Iodine Iodine is very important precursor for thyroid hormones. The receptors for iodine is present throughout the body which regulate the cellular metabolism like nutrition into cells and helps to remove toxins from cells.