A 5 year old female patient complains of deformed shape of legs. Patient is a strict vegetarian. Lab investigations reveal elevated level of alkaline phosphatase. This patient may be suffering from deficiency of-

Deficiency of vitamin D causes rickets in children and osteomalacia in adults. The weight bearing bones are bent to form bow-legs. In rickets, the plasma level of calcitriol is decreased and alkaline phosphatase activity is elevated. Satyanarayana- Biochemistry, 3rd edition, pg-127