The correct answer is Both 1 and 2. Important Points The deficiency of one or more nutrients can cause diseases or disorders in our body. Diseases that occur due to a lack of nutrients over a long period are called deficiency diseases. Hence statement 1 is correct. Eg. Rickets is caused due to deficiency of vitamin D. All deficiency diseases can be prevented by taking a balanced diet. Iodine deficiency is the most common cause of thyroid enlargement and goitre. Hence statement 2 is correct. Goitre is an enlargement of the thyroid gland. Iodine is essential for the production of thyroid hormones. Additional Information Iodine: Iodine is an essential trace element in biological systems. It has the distinction of being the heaviest element commonly needed by living organisms. Iodine is critical to the proper functioning of the vertebrate endocrine system, and plays smaller roles in numerous other organs, including those of the digestive and reproductive systems. Fish (such as cod and tuna), seaweed, shrimp, and other seafood, which are generally rich in iodine. Iodized salt, is a very common source of Iodine. Iodine deficiency is the most common cause of thyroid enlargement and goitre.