- Vitamin D deficiency is the primary cause of rickets in pediatric patients because it leads to impaired calcium and phosphate absorption from the intestine.
- This results in defective mineralization of the growing bone matrix, causing the hallmark features of rickets such as bone pain, deformities, and delayed growth.
- Vitamin D is essential for maintaining adequate serum calcium and phosphate levels necessary for normal bone development during childhood.
- Without sufficient vitamin D, osteoid tissue accumulates but fails to mineralize properly, leading to the clinical and radiological manifestations of rickets.

Reference: Davidson’s Principles and Practice of Medicine, 23rd Edition, Chapter: Disorders of Bone and Mineral Metabolism, Page 860.