Topic 2 Chemical Elements and Human Health

Topic 2

Chemical Elements and Human Health 

We often see food and health products marked with words such as "calcium supplement", "iron supplement", "zinc supplement" and "iodine supplement" on the shelves of shopping malls. It can be seen that many chemical elements are closely related to our health. There are more than one hundred elements in the periodic table, which ones are necessary for us? Which are harmful to health? Let us find the answer together in the study of this topic.

All life originates from nature and is always exchanging matter and energy with the external environment. Human beings are no exception. More than 50 elements in the human body can be found in nature. There are 11 kinds of elements with high content in the human body, which account for about 99.95% of the body mass. Elements with a content of more than 0.01% in the human body are called macro elements; elements with a content of less than 0.01% are called trace elements. Although the content of some trace elements in the human body is very small, it is necessary to maintain normal life activities. In the human body, the four most abundant elements are oxygen, carbon, hydrogen, and nitrogen, and the remaining elements mainly exist in aqueous solution in the form of inorganic salts. Some of them are important materials that constitute human tissues; some can regulate the metabolism of the human body and promote health.

Calcium is the metal element with the highest content in the human body and an important component of the human body. The adult human body contains about 1.2kg of calcium, 99% of which exists in bones and teeth, mainly in the form of calcium hydroxyphosphate [Cal0(PO4)6(OH)2] crystals, which make bones and teeth have a hard structural support. Calcium deficiency in young children and adolescents will cause rickets and stunting, and calcium deficiency in the elderly will cause osteoporosis and fractures easily. Therefore, the human body must take in a sufficient amount of calcium every day. Adolescents are in the stage of growth and development and need to consume more calcium than adults. Foods such as milk, dairy products, beans, and shrimp skins are rich in calcium and are a good source of calcium in the daily diet. Patients with osteoporosis and rickets caused by calcium deficiency should take calcium tablets and other calcium supplements under the guidance of doctors.

Sodium and potassium also play an important role in human health. The human body contains 80-120 g of sodium, half of which exists in the extracellular fluid in the form of Na*, while potassium in the human body mainly exists in the intracellular fluid in the form of K*. Na* and K+ in the extracellular fluid and intracellular fluid each maintain a certain concentration, which plays an important role in maintaining water in the human body and maintaining a constant pH of the body fluid (such as the pH of plasma is 7.35-7.45), which is the human body Necessary to maintain normal life activities.

After studying this topic, you should know

1,The human body is composed of more than 50 elements, which can be divided into macro elements and trace elements according to the content. Major elements and some trace elements are necessary for the human body. They can regulate the metabolism of the human body, promote the health of the body, and some are important materials that constitute human tissues.

2,For the essential elements of the human body, we should also pay attention to reasonable intake. Insufficient or excessive intake is not conducive to human health.

3,Preventing harmful elements from harming the human body is an important guarantee for human's healthy life.