An abnormality in children caused by the deficiency of calcium in their bones is termed as rickets. Calcium deficiency can occur due to less calcium intake through diet and inadequate exposure to sunshine. This is because sunshine is needed for making Vitamin D, which is an important nutrient required for absorption of calcium. Animal foods such as egg yolk and other dairy products contain plenty of this nutrient.
Vitamin D is fat-soluble by nature and is produced by our skin when it is exposed to ultraviolet rays of the sun. The vitamin thus produced is then transformed into its active form so that it functions as hormone and influences the absorption of calcium by the intestine. It is also capable of regulating calcium levels in the bones. When the body lacks Vitamin D, calcium absorption is not properly taken care of and this will result in bone damage. This is the condition we call as rickets.
Another mechanism in the body starts functioning when there is a downfall in the level of calcium in blood. The parathyroid gland, situated in the neck, starts functioning in order to regulate this lowered blood calcium level. As a result, calcium present in the bones gets destroyed. This will further deteriorate the condition.
Sunlight plays an important role in the production of this nutrient. Due to this reason, lack of proper exposure to environmental conditions with plenty of daylight and staying indoors for a very long time also increases the risk of lowered production of Vitamin D. Reduced rate of digestion and limited fat absorption can also result in deficiency of Vitamin D that is absorbed from food.
Because vitamin D is a fat-soluble vitamin, conditions that reduce digestion or absorption of fats will decrease the ability of vitamin D to be absorbed from the intestines. When the body is deficient in Vitamin D, it is unable to properly regulate calcium and phosphate levels. Vitamin D may occasionally lack in those people who strictly follow a vegetarian diet and do not consume enough milk. Certain people will be lactose intolerant, as their digestive system will have difficulty in digesting milk products. In such cases of dietary lack, Vitamin D is likely to fall down.
Hereditary rickets is a genetically transferred form of this disorder and is caused when the kidneys fail to retain phosphate. Renal tubular acidosis and such other kidney related disorders might also lead to rickets.