The main causes and distribution of hypervitaminosis D in children

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More than half a century has passed since the opening of vitamin D. For this period are well studied diverse positive influence on the body. Along with this already in 1928-1930, there were reports of severe poisoning drugs irradiated ergosterol (Hess, Lewis, 1928; Shohl a. oth., 1930 and others). Pathological conditions that arise from the use of massive doses of vitamin D, L. J. Harris, T. Moore (1928) and A. W. Ham (1932) proposed to be called hypervitaminosis Few Days later along with this have been widely use the term "D-vitamin intoxication". However, most researchers and clinicians prefer to use the first name.
In domestic and foreign literature the study of hypervitaminosis D, in particular pathogenesis, treatment and prevention in the spotlight. The relevance of the issue confirmed by numerous experimental and clinical studies of such specialists, biologists, biochemists, pediatricians pathomorphologic, therapists, etc. However the greatest interest to the study of this question are pediatricians, because in recent years due to the wide use of vitamin E for the prevention and treatment of rickets is more often began to be observed symptoms of hypervitaminosis D in children of early age, which is confirmed by numerous researches of domestic and foreign authors (Vishnevsky, 1965; bluegrass, 1966; Strukov, 1967; Vodila, 1968; Harris, 1969; Sapronick, charyeva, 1971).
Before the opening of vitamin D mankind did not know of the problem gipervitaminoza D. Its appearance was connected with the widely established the production of vitamin D and its intensive use in medicine for prophylaxis and treatment of various diseases. This was facilitated by the fact that in medical practice, the most widespread are concentrated vitamin D. Thus, the medical industry in the UK produces 26 different types of tablets and capsules. Of these, only three drugs have less than 300 ME, the others are available in doses much higher than the physiological need for this vitamin (Taylor, 1972).
Most researchers believe that the main reasons behind the emergence and relatively high rate of hypervitaminosis D, are the following.
1. Extremely high biological activity of vitamin D and relatively small physiological need in it.
2. Most absorption rate and the lack of effective ways of removing it from the body.
3. Insufficient awareness of the population and some medical staff of the high toxicity of the drug.
4. Insufficiently justified the appointment of high doses for the prevention and treatment of rickets. In particular, in recent decades widely used method of shock doses", "method of vitamin aftershocks", "sealed courses on" application of vitamin D (Krestin, 1945; Balabekova, 1970, and others).
When these methods recommended dose rate vitamin D - 600 000 ME - can be given for 6-12 days, 50 000 ME - 12, 100 000 IU (1 per day) for 7-10 days, and so on
On the hypervitaminosis D is also affected by the method of taking the drug. Morgan (1974, CIT. on Ushakova, and others, 1961) observed the death of the puppies after single dose of vitamin D2 in a dose of 10 mg/kg of body weight. If this dose puppies get fractional method, the toxic effect of the drug was even stronger. However, recently appeared in the literature reports that even a single dose of high doses of vitamin D can cause serious side effects (Spirichev, 1973).
One of the main causes of hypervitaminosis D, in our opinion, is that still there is no consensus about the doses of vitamin D used for prevention of rickets. Even in countries, republics and regions located in the same climatic zone, the recommended prophylactic doses of vitamin D vary from 400 to 60 000 ME in the day. Thus, M. S. Maslov (1952) is considered a sufficient dose of 600 to 1000 IU of vitamin D and warned of pediatricians from Hobbies high doses of this drug.