A routine supplementation of vitamin D in neonates is being increasingly endorsed by various international organizations [1]. We conducted this study to determine the cord blood 25-hydroxy vitamin D levels of term healthy neonates born in Malabar Institute of Medical sciences, Kozhikode, Kerala during the summer months of March and April 2013.

Fifty neonates, born at term, whose mothers (mean age 28 yrs) were on antenatal follow up from this institution enrolled for the study. They had received a daily supplementation of 1000 mg calcium and 200 IU vitamin D from 12 weeks of gestation onwards. We excluded neonates with asphyxia, those needing admission to intensive care unit, and those with congenital anomalies. Cord venous blood (5 mL) was collected immediately and 25-hydroxy vitamin D levels were analyzed by Chemiluminescent micro particle immunoassay using DiaSorin liaison equipment. Maternal data were collected using electronic medical records and a questionnaire. Birth weight, sex and mode of delivery were recorded at the time of sample collection. All babies were supplemented with vitamin D at discharge. Prior informed consent was obtained from the parents and clearance was obtained from Institute ethical committee. Statistical analysis was performed with the SPSS version 16.0; P value less than 0.05 was considered statistically significant.

We enrolled 50 neonates (22 males) with mean birth weight of 2870 g. Vitamin D levels were normally distributed with a mean (SD) value of 11.36 (4.75) ng/mL, and median (range) value of 10.85 (3.9-24.9) ng/mL. As per US Endocrine Society classification [1], 47 (94%) had vitamin D deficiency (<20 ng/mL). The remaining three had vitamin D insufficiency (21-29 ng/mL). Significantly higher cord vitamin D level were seen in primiparous mothers, and mothers with gestational diabetes (Table I).

TABLE I Comparison of Cord Blood 25-Hydroxy Vitamin D Levels in Different Groups

Neonates in this study had a lower mean value of cord blood 25-hydroxy vitamin D levels than that has been reported in other studies [2,3]. Maternal level is the single most important factor that influences neonatal vitamin D levels [4-6], especially the third trimester levels [5,6]. We did not measure 25-hydroxy vitamin D levels in mothers, and this was a limitation. Other limitations were small sample size and lack of follow-up.

This study shows that even in a tropical climate, neonates suffer from vitamin D deficiency. We recommend larger studies in different settings with follow-up of neonates found to be vitamin D deficient.

Contributors: AMR: Study conception, data collection, data analysis and manuscript writing; DeN: study conception, data collection and analysis; DiN: Data collection and analysis; PR: Study conception, data collection and manuscript writing. All authors approved final version of manuscript.

Funding: Eris Montana Pharmaceuticals; Competing interests: None stated.

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2. Bhalala U, Desai M, Parekh P, Mokal R, Chheda B. Subclinical hypovitaminosis D among exclusively breast fed young infants. Indian Pediatr. 2007; 44:897-901.

3. Palmer EG, Ramirez-Enriquez E, Frioux SM, Tyree SM. Vitamin D deficiency at birth among military dependants in Hawai’i. Hawaii J Med Public Health. 2013;72:88-91.

4. Novakovic B, Galati JC, Chen A, Morley R, Craig JM, Saffery R. Maternal vitamin D predominates over genetic factors in determining neonatal circulating vitamin D concentrations. Am J Clin Nutr. 2012;96:188-95.

5. Aly YF, El Koumi MA, Abd El Rahman RN. Impact of maternal vitamin D status during pregnancy on the prevalence of neonatal vitamin D deficiency. Pediatr Rep. 2013;5:e6.