Clinical Responses to a Mega-dose of Vitamin D3 in Infants and Toddlers With Vitamin D Deficiency Rickets

Objectives: Was to investigate the effect of treatment with an IM injection, a mega dose of vitamin D3 (10 000 IU/kg) on the clinical, biochemical and radiological parameters of 40 rachitic children with vitamin D deficiency (VDD) over a period of 3 months. Design: In this prospective study we evaluated the clinical, biochemical and radiological responses of an IM injection of cholecalciferol (10 000 IU/kg) for 3 months. Results: At presentation, the most frequent manifestations were enlarged wrist joints, hypotonia, irritability, cranial bossing, wide anterior fontanel, bow legs, delayed teething and walking and Harrison's sulcus with chest rosaries. Short stature (length SDS < −2) was recorded in 30% of patients. Craniotabes and hypocalcemic tetany were the least common presentations. In VDD children the most frequent biochemical abnormality was high alkaline phosphatase (ALP) (100%), followed by low phosphate (PO4) (75%) and low calcium (Ca) (12.5%). One month after treatment, serum Ca, PO4 and 25(OH)D concentrations were normal. Three months after the injection, serum level of ALP and parathormone (PTH) decreased to normal. The majority of patients (87.5%) had serum 25(OH)D level ≥ 20 ng/ml, but some (12.5%) had level