2. The main sources of various inorganic salts and their main manifestations in the absence.
(1) sodium
Sodium is the main component of salt. China Nutrition Society recommended/kloc-The appropriate sodium intake for adults over 0/8 years old is 2.2g per day, and the elderly should eat light food. Sodium is ubiquitous in all kinds of foods. The main sources of sodium in human body are salt, soy sauce, pickled food, smoked food and salty food.
(2) Calcium
Calcium is an important component of bones. Calcium deficiency can lead to osteomalacia and osteoporosis. China Nutrition Society recommended that the appropriate daily intake of calcium for adults aged 18-50 is 800mg；; The taste of middle-aged and elderly people after 50 years old is 1000 mg. Common foods rich in calcium are milk, yogurt, oatmeal, sea cucumber, shrimp skin, wheat, bean flour, bean products, day lily and so on.
(3) Magnesium
Magnesium is an essential element to maintain the structure and function of bone cells. Magnesium deficiency can lead to nervous tension, emotional instability, muscle tremor and so on. China Nutrition Society recommended/kloc-the suitable daily intake of magnesium for adults over 0/8 years old is 350 mg. Common foods rich in magnesium are fresh green leafy vegetables, nuts and coarse grains.
(4) Phosphorus
Phosphorus is an important component of bones and teeth. Severe phosphorus deficiency can lead to anorexia and anemia. China Nutrition Society recommended that the appropriate daily intake of phosphorus for adults over 0/8 years old/kloc is 700 mg. Common phosphorus-containing foods include lean meat, eggs, milk, animal offal, kelp, peanuts, nuts and coarse grains.
(5) Iron
Iron is the most abundant trace element in human body, which is closely related to human life and health. Iron deficiency can lead to iron deficiency anemia and decreased immunity. China Nutrition Society recommended that the suitable daily intake of iron for men or women over 50 years old is 7 15 mg. Common iron-rich foods include animal liver, kidney, caviar, lean meat, potatoes, wheat bran and so on.
(6) iodine
Iodine is a component of thyroid hormone. Iodine deficiency can lead to dementia, goiter and hyperthyroidism in children and adults. The China Nutrition Society recommended that 150 mg of iodine should be suitable for adults over 8 years old. Common foods rich in iodine include seafood, such as kelp, laver, scallop and sea cucumber. Residents in coastal areas often eat seafood and residents in inland areas eat iodized salt, which is the most economical, convenient and effective way to ensure the balance of iodine metabolism.
(7) Zinc
Zinc can promote growth and development. Zinc deficiency in children will lead to poor growth and development; Zinc deficiency in pregnant women will lead to brain dysplasia and mental retardation in infants, even after birth. The China Nutrition Society recommended that the suitable daily intake of zinc for adult men is 15.5 mg, and that for adult women is 1 1.5 mg. Common foods rich in zinc are liver, meat, eggs and oysters.
Inorganic salts are mineral nutrients existing in the body and food, which are composed of organic and inorganic substances. More than 20 kinds of essential inorganic salts have been found in human body, accounting for about 4 ~ 5% of human body weight. Among them, there are seven kinds of calcium, phosphorus, potassium, sodium, chlorine, magnesium and sulfur (> 5g). The daily dietary requirement is above 100mg, which is called a macroelement. Others are low in content. With the development of modern analytical technology, trace elements such as iron, iodine, copper, zinc, manganese, cobalt, molybdenum, selenium, chromium, nickel, silicon, fluorine and vanadium are found by atomic absorption spectrometry, neutron activation method and plasma emission spectrometry. The daily dietary requirement of μ g ~ mg is called trace elements.
The distribution of inorganic salts in the body is extremely uneven. For example, most of calcium and phosphorus are in hard tissues such as bones and teeth, iron is concentrated in red blood cells, iodine is concentrated in thyroid, barium is concentrated in adipose tissue, cobalt is concentrated in hematopoietic organs, and zinc is concentrated in muscle tissue.
Inorganic salts are very important to the structure of tissues and cells. Hard tissues such as bones and teeth are mostly composed of calcium, phosphorus and magnesium, while soft tissues contain more potassium. Inorganic salt ions in body fluids regulate the permeability of cell membrane, control water, maintain normal osmotic pressure and acid-base balance, help transport common elements to the whole body, and participate in nerve activity and muscle contraction. Some of them are inorganic or organic compounds, which constitute auxiliary groups of enzymes, hormones, vitamins, protein and nucleic acids, or as activators of various enzyme systems, and participate in many important rearrangement functions. For example, maintaining the activity of the heart and brain, helping the formation of antibodies, and playing a beneficial role in the human body.
Due to metabolism, a certain amount of inorganic salts are excreted through various channels every day, so it must be supplemented by diet. The metabolism of inorganic salts can be judged by analyzing the concentration in blood, hair, urine or tissues. The functions of inorganic salts in human body are interrelated. In a suitable concentration range, it is beneficial to the health of people, animals and plants. Lack or excess will cause diseases, and diseases affect their metabolism and often increase their consumption. Deficiencies of calcium, iron and iodine are common in China. Selenium and fluorine vary with geochemical environment, including deficiency diseases such as Keshan disease, Kaschin-Beck disease and biting teeth, as well as excessive diseases such as fluorosis and selenium poisoning.