Chemical elements are closely related to human life, and the content of chemical elements in human body directly affects human health. According to your existing knowledge, try to complete the followi

Chemical elements are closely related to human life, and the content of chemical elements in human body directly affects human health. According to your existing knowledge, try to complete the following. (1) iodine, zinc, iron and calcium.

(1) iodine is the main component of thyroid hormone synthesis, and goiter will occur if it is lacking.

(2) Zinc affects physical development. Zinc deficiency can lead to loss of appetite, growth retardation and stunting, so it is easy to become a dwarf.

(3) Iron is the main component of hemoglobin synthesis.

(4) Calcium mainly exists in human bones and teeth and is a solid structural support in human body, so it is called white "reinforced concrete" in human body.

Therefore, the answer is: (1) iodine; (2) zinc; (3) iron; (4) calcium.