Sodium iodide is a chemical compound made up of sodium and iodine, represented by the formula NaI. It appears as a white, crystalline solid and is highly soluble in water. Sodium iodide is commonly used in various applications, including as a dietary supplement to prevent iodine deficiency and in medical imaging as a radiopharmaceutical. In laboratories, sodium iodide is often utilized in organic synthesis and as a reagent in chemical reactions. It can also be found in some types of salt, known as iodized salt, which helps ensure adequate iodine intake in diets.