Vitamin D deficiency Osteoid tissue Less ca absorbed from the intestin failure to mineralize Serum ca concentration decrease Osteoid tissue Parathormone accumulation secreted Urine phosphorus Low Mobilized increased serum bone ca p phosphor Normal o' Slight decrease in serum calcium concentration Serum AKP Vitamin D-deficient increased Rickets Pathophysiology of Vitamin D-deficient RicketsVitamin D deficiency Osteoid tissue failure to mineralize Osteoid tissue accumulation Less Ca absorbed from the intestine Urine phosphorus increased Parathormone secreted Serum AKP increased Mobilized bone Ca,P Vitamin D-deficient Rickets Serum Ca concentration decrease Low serum phosphor us Pathophysiology of Vitamin D-deficient Rickets Normal or slight decrease in serum calcium concentration