Serum Vitamin D Status and Outcome among Critically Ill Children Admitted to the Pediatric Intensive Care Unit in South India.

Objectives: To determine the vitamin D status and the association between vitamin D status and the clinical outcome of critically ill children admitted to pediatric intensive care unit (PICU) in South India.

Methods: Fifty-four consecutive children with medical and surgical diagnoses were included with parental consent. Severity of illness was assessed using PIM-2 score; Sequential Organ Failure Assessment Cardiovascular Score (CV-SOFA) was used to describe vasopressor use. Serum for 25(OH) D levels was obtained as close as possible to the ICU admission. Vitamin D deficiency was defined as serum 25(OH) D level < 20 ng/ml (50 nmol/L). Primary outcome measures were serum 25(OH) D level and in-hospital all cause mortality. Secondary outcomes were illness severity, vasopressor requirement, use of mechanical ventilation and duration of ICU stay.

Results: Of the 54 children, two were excluded due to insufficient serum for vitamin D analysis. Median age was 17.5 mo (IQR = 4.5-78); 38.5 % were infants. Higher age was associated with low vitamin D levels (r s  = -0.34; p 0.01). Median serum 25(OH) D level was 25.1 ng/ml (IQR = 16.2-34.2). Shock (30.8 %), CNS conditions (23.1 %) and respiratory illnesses (21.2 %) were the three most common reasons for admission to the PICU. Vitamin D deficiency was seen in 40.3 % of the critically ill children. Higher PIM score or SOFA score were associated with low vitamin levels (r s  = -0.29, p 0.04 and r s  = -0.29, p 0.05 respectively). Children who were mechanically ventilated had a significantly lower median serum 25(OH) D level than those who were not on ventilation [19.5 ng/ml (IQR = 14.6-27.7)] vs. 32.1 ng/ml[(IQR = 16.5-50.9), p 0.01]. Serum 25(OH) D level was also positively associated with serum calcium levels (r s = 0.32, p 0.03). The proportion of children who died or were discharged terminally at parental request was 23.8 % among those with serum 25(OH) D level < 20 ng/ml as compared to 16.1 % among those with serum 25(OH) D level > 20 ng/ml (p 0.49).

Conclusions: Vitamin D deficiency is common among pediatric patients admitted to PICU in South India. Low serum 25(OH) D level was associated with higher severity of illness, need for mechanical ventilation, more vasopressor use and lower serum calcium levels. No association between vitamin D status and mortality was demonstrated.