See also: Bone endocrine diseases
Defective mineralization of the bone
Softening of the bone
Development of deformities, particularly in the weight-bearing bones of the lower extremities
Rickets is characterized by defective mineralization of both bone and growth plate cartilage. It is also caused by vitamin D deficiency, but is seen only in children.
Classic radiologic features
Symmetrical "looser zones"
Blurring of the spine
25-OH Vitamin D | Low
PTH | High
Ca2+ | Low or Low-normal
Phosphate | Low
May be caused by
Renal tubular acidosis
Vitamin D deficiency
Vitamin D deficiency leads to decreased inestinal calcium and phosphorus absorption, thereby resulting in hypocalcemia and hypophosphatemia. Hypocalcemia then stimulates the parathyroid glands. The resultant secondary hyperparathyroidism brings the serum calcium levels to normal or near-normal (especially in the early stages), and increases urinary phosphate excretion, thereby worsening the hypophosphatemia. Vitamin D deficiency thus causes more marked hypophosphatemia than hypocalcemia, especially in the early stages.
See also: Vitamin deficiencies, bone endocrine diseases