Vitamin D is essential for normal growth and development in children. Vitamin D deficient rickets. This type usually results from a dietary deficiency of vitamin D, usually coupled with inadequate exposure to sunlight. Hypophosphatemic vitamin D resistant rickets. It is caused by the inadequate re-absorption of phosphate in the proximal tubule of the kidneys.
Affected children have a very short stature, with dramatic bowing of the legs.
Type I vitamin D dependent rickets. Rickets may occur when the supply of vitamin D is inadequate, its metabolism is abnormal, or the body is resistant to its actions. In vitamin D deficient rickets, the reduced vitamin D intake causes a decrease in the absorption of calcium from the GI tract. In hypophosphatemic vitamin D resistant rickets, there is a physiologic problem with the re-absorption of phosphate from the proximal tubule of the kidneys. Infants with vitamin D deficiency experience decreased growth, short stature, bowing of the legs, and poor weight gain.