We thank the authors for the interest in our article. Some of the methodological details and results of the study were not included in the manuscript due to the word limit. We regret the errors in the abstract of this article, and thank the readers for pointing them out.

We agree with the comment regarding possibility of low vitamin D level in children with chronic disease/ drug intake for chronic conditions. Many of the children admitted to our intensive care unit had an underlying chronic illness. These conditions were: chronic liver disease (16), congenital heart disease (14) , metabolic disorder (9), congenital malformation (6), type-1 diabetes mellitus (6), asthma (4), tuberculosis (6), HIV (4), rheumatological diseases (6), cystic fibrosis (4), primary immunodeficiency (2) and others (9).

Many of the illnesses in childhood are associated with low Vitamin D levels. If we had excluded the children admitted with underlying/ chronic illnesses like liver disease and neurological disease, we would have been left with small subset of population in our sample. As children with central nervous system infections and liver disease contribute significantly to intensive care hospitalizations in tropical countries, we did not exclude these conditions in order to get a true picture of vitamin D status in intensive care settings.

Most of the children who were vitamin D-deficient were also deficient in calcium. One of the objectives of the study was to characterize vitamin D deficiency status in relation to parathyroid response; therefore we presented data of, only those children who were vitamin D- deficient. We agree with your comment regarding importance of iCa levels in critical illness. It was not feasible to measure iCa in all the patients in our study. Blood samples for laboratory investigations (Calcium, PTH, Vitamin D, etc) were collected at the baseline at the time of admission. Therefore, calcium supplementation in hypocalcemic patients after PICU admission would not alter the laboratory values of calcium, PTH or vitamin D. Children with hypocalcemia were managed based on the unit protocol, supported by the clinical profile.

Regarding feeding status, most of the children consumed animal milk [local dairy company (28.6%); direct milk from animal sources (24.7%)]. Seven percent of the children were on commercially available formula feeds, 11.7% were on breast feed and 28% of children were on both formula and breast feeds. Those fed on both breast feed and formula were less likely to be vitamin D deficient compared to other types of milk supplementation.