Rickets

Rickets is a disease of childhood and adolescence, which is characterized by incomplete mineralization of bone under the deficiency of vitamin D. This is due to calcium loss from bones, which are flexible and deforms.
Rickets occurs mainly in children between 3 months and 2 years, during which the child grows quickly and its body requires a high level of calcium and phosphorus. The condition is rare in newborns.Vitamin D allows calcium intestinal absorption, bone mineralization acting on, and on urine calcium excretion. Most vitamin D is synthesized in the epidermis, where inactive sterols are activated by ultraviolet rays.
Causes of rickets:
The main cause of rickets is vitamin D deficiency during childhood.Vitamin D is a fat-soluble vitamins (fat soluble), which can be absorbed from the intestines or the skin may be produced when skin is exposed to sunlight (UV rays contribute to vitamin D synthesis by the body). Vitamin D is converted assimilated into its active form, functioning as a hormone that regulates calcium absorption from the intestines and that regulates the calcium and phosphorus in bones. When these minerals in the blood level is too low to destroy bone matrix protein.
In rickets, another mechanism comes into operation to increase blood calcium level. Parathyroid glands (four glands located behind the thyroid hormone) increase its functioning to compensate for low levels of calcium in the blood. To increase the level of blood calcium, bone calcium destroys the hormone, resulting in further loss of calcium and phosphorus in bones. In severe cases, cysts may develop in the bones.
 Vitamin D deficiency can have several causes:
environmental factors: limited exposure to the sun, winter, temperate, etc..vitamin D in dietintestinal malabsorption (steatorrhea) - the body can not absorb fats, which went directly into the feces. Thus, vitamin D, which is usually absorbed with fat and calcium are poorly absorbed.Renal tubular acidosis - increase the amount of acid in body fluids due to a congenital or acquired kidneylack of calcium and phosphorus in the diet favors the appearance of ricketsa dietary deficiency of vitamin D may occasionally occur and vegetarians who do not consume dairy products, or people with lactose intolerance.