Vitamin D Deficiency and Parathyroid Response in Critically-ill Children: Authors Reply.

Though the authors have excluded patients with known parathyroid disease, rickets, renal tubular acidosis, chronic kidney disease or a diagnosis of acute kidney injury at admission, about 56% children were stated to have some underlying chronic illness. One would be really interested to know the nature of these chronic illnesses, as many diseases such as chronic liver disease [2] and nephrotic syndrome [3] are known to have low vitamin D levels. The authors have also not mentioned whether any of these children with chronic diseases were on long-term medications known to affect vitamin D-calciumparathyroid axis such as Cortisteroids for nephrotic syndrome, Rifampicin for tuberculosis, and antiepileptics for epilepsy [4]. Authors stated that 15 patients were admitted with liver disease and 24 with neurological diseases; the disease condition and/or the medication used in these children can lead to a decrease in vitamin D and calcium levels.