Magnesium metabolism in hypervitaminosis D

As is known, the composition of human blood is characterized by a great constancy. Only with a stable composition of the internal environment of the body possible smooth and uninterrupted operation of different systems. First of all it concerns calcium and magnesium metabolism. The change in the level of Ca and Mg in the blood causes serious consequences. Thus, the decrease in the concentration of the first causes seizures, paralysis, tetany; a significant decrease in the number of second (Mg) may be the cause of sudden death in children (Caddell, 1972). The increase in the content of these electrolytes leads to serious biochemical shifts tissue calcification with violation of the kidneys, and other organs and systems.
The relationship between calcium and magnesium metabolism known since 1909, when L. C. Mendel and S. C. Beni-dict found that the loss of Ca with urine increased from the parenteral administration of magnesium, a Mg - after infusion of calcium. There are few works that deal with the exchange of magnesium in hypercalcemic States. They emphasize that increasing the concentration of Ca in blood is accompanied by enhanced Mg excretion with urine and development gipomagniemii (Samiy, Brown, 1960; Hendrix, 1966; Clark, 1968; Strukov, Rakhimov, 1974).
Considering the aforementioned, it is interesting to provide data for the study of magnesium metabolism in connection with phosphorus-calcium metabolism. Under the supervision was 52 children with Dr. vitamin a intoxication. Most children (46) clinic of hypervitaminosis D (HBV-E) was due to exchange rate overvaluation preventive and curative doses of vitamin D: 3-16 times longer than recommended. Children ages 2 to 19 months. Boys was 29, girls - 23. Most children with Dr. vitamin a intoxication received artificial (20) and mixed (21) breastfeeding. Status light in 7 (group I), moderate - 26 (group II) and heavy - at 19 children (group III). At the same time, we have studied indicators Mg, Ca, P 30 healthy children (a control group). The research results are presented in table 1.
As can be seen from table 1, with increasing severity D-vitamin intoxication increased number of Ca in the serum of patients with severe hypervitaminosis D - to 14.9 ±0,71, in the control group-a 10.1+0.27 mg%. Also set the parallelism in the content of Mg and P concentrations with increasing severity of intoxication significantly fell in comparison with indicators of the Ca. Even at easy forms of hypervitaminosis D shifts in the content of magnesium in the serum was demonstrative than calcium. More significant changes magnesium currency were for moderate and severe forms of the disease. Thus, when gipercalziemia developed on soil D-vitamin intoxication, also decreases the concentration of magnesium in serum. This index, along with hypophosphatemia is one of the sensitive and reliable indicators gipervitaminoza D.
It should be emphasized that hypermagnesemia and hypophosphatemia persist over a long time after the drug of vitamin D. Thus, the calcium content in the blood of most children (49) normalized 10 - 14 day stay in hospital, while half of the patients (27) the concentration of P and Mg was reduced even through 1 to 1.5 months. Therefore, these tests are more important in a retrospective diagnosis of hypervitaminosis D, than the definition of the Ca in the blood.
On the basis of the conducted research it can be concluded that when hypervitaminosis D clearly expressed calcium-magnesium antagonism. With increasing concentration of calcium reduces the content of magnesium in serum that may be used to diagnose D-vitamin intoxication. At the same time noted the close relationship and synchronicity in phosphate and magnesium metabolism. Thus, the number of Mg in the blood is reduced accordingly decreasing concentrations of inorganic R.
Normalization Ca content in blood is on 5-12 day after drug withdrawal of vitamin D. Violations in the exchange of Mg and R more stable. In a half of patients with hypervitaminosis D their content has not reached normal values even in 1-1,5 months.
Thus, determination of serum concentrations of phosphorus and magnesium can be used for retrospective diagnosis gipervitaminoza D.