Water and water-salt metabolism( III)

Re-adsorption of calcium in the renal tubules and the release of calcium from the bones increases parathyroid hormone parathyroid hormone, which leads to an increase in the concentration of calcium in the blood. Thyreocalcitonin( thyroid hormone) increases the excretion of calcium by the kidneys and promotes calcium transfer to the bone, which in turn reduces the concentration of calcium in the blood. The active form of vitamin D, which is involved in the regulation of calcium metabolism, is formed in the kidneys.

The level of chloride in the blood plasma is regulated with the participation of aldosterone. The chlorine reabsorption increases with increasing sodium reabsorption. Chlorine can be released independently of sodium.

It is necessary to maintain the usual balance between losses and water consumption in the body.

The loss of water and salts, which causes disturbances in the process of body thermoregulation( for example, in an athlete), is an important factor that can limit high physical performance. At an ambient temperature of 20-25 degrees, the athlete weighing 70 kg with moderate physical activity for 1 hour, the loss of water reaches 1.5 - 2 liters. In the absence of thermoregulation, such a load could raise the body temperature 11 degrees above normal.

The competition load causes an increase in the level of lactic acid in the blood. For rapid recovery in this situation, it is recommended to use K, Mg and Ca salts, which are contained in vegetables, fruits or dried fruits.

Natural waters depending on the level of their ions are divided into fresh( with total mineralization not exceeding 1 g / l), mineralized( from 1 to 50 g / l) and brines( above 50 g / l).

The constant use of mineralized water( 1.5-3 g / l dry residue) in food causes an increased hydrophilicity of the tissues, a delay in the body's drinking water and a decrease in diuresis by 30-60%.Also, water with increased mineralization has a negative effect on the secretory activity of the stomach and violates the water-salt balance in the body. This water less satisfies thirst. Studies have shown that suppression of gastric secretion, a decrease in diuresis and an increase in blood pressure can be caused by excess intake of chlorides with water, especially sodium chlorides.

The increased content of sulphates in drinking water causes disturbance of the input-salt metabolism and leads to the appearance of dyspeptic phenomena( from slight indulgence to pronounced).

The organism's homeostasis can be maintained at the lower limit of mineralization with a dry residue of 100 mg / l, and the optimum level of mineralization is 200-400 mg / l. The content of calcium and magnesium must be at least 25 mg / l and 10 mg / l, respectively. .. more

Materials used:
Shilov VN, Mits'yo VP"Healthy food"