Vitamin D Status and Factors Associated with Vitamin D Deficiency during the First Year of Life in Preterm Infants

[Expert consensus on enteral nutrition management of preterm infants (2024)]

Providing adequate and balanced nutrition for preterm infants, especially extremely/very preterm infants, is the material basis for promoting their normal growth and development and improving long-term prognosis. Enteral nutrition is the best way to feed preterm infants. Previous systematic reviews have shown that using evidence-based standardized feeding management strategies can effectively promote the establishment of full enteral feeding, reduce the duration of parenteral nutrition, improve the nutritional outcomes of preterm infants, and not increase the risk of necrotizing enterocolitis or death. Based on relevant research in China and overseas, the consensus working group has developed 20 recommendations in 5 aspects including the goal of enteral nutrition, transitioning to enteral nutrition, stable growth period enteral nutrition, supplementation of special nutrients, and monitoring of enteral nutrition for preterm infants, using the Grading of Recommendations Assessment, Development and Evaluation. The aim is to provide recommendations for healthcare professionals involved in the management of enteral nutrition for preterm infants, in order to improve the clinical outcomes of preterm infants.

[Vitamin D level in umbilical cord blood of late preterm infants and the effect of vitamin D3 supplementation on the behavioral development of infants and young children: a prospective randomized controlled study]

OBJECTIVES

To investigate the level of 25 hydroxyvitamin D [25(OH)D] in late preterm infants and the effect of vitamin D₃ supplementation on the neurobehavioral development of infants and young children.

METHODS

In this prospective study, 161 late preterm infants who were admitted from June 2017 to June 2020 were enrolled. According to the level of 25(OH)D in umbilical cord blood, they were divided into three groups: sufficiency group (n=52), insufficiency group (n=53), and deficiency group (n=56). Each group was further divided into subgroup A (vitamin D₃ 800 IU/d) and subgroup B (individualized vitamin D₃ supplementation) using a random number table. The levels of 25(OH)D were measured at 3 months after birth and at the corrected ages of 10 months and 18 months. The neurobehavioral development levels were determined by the Gesell Developmental Scale at the corrected ages of 10 months and 18 months.

RESULTS

Within 24 hours and 3 months after birth, the insufficiency group and the deficiency group had a significantly lower level of 25(OH)D than the sufficiency group (P<0.05), and the insufficiency group had a significantly higher level of 25(OH)D than the deficiency group (P<0.05). In the deficiency group, subgroup B had a significantly higher level of 25(OH)D than subgroup A (P<0.05) at 3 months after birth. At the corrected ages of 10 months and 18 months, the insufficiency and deficiency groups had significantly lower scores of five functional areas of the Gesell Development Scale than the sufficiency group (P<0.05). Compared with the insufficiency group, the deficiency group had a significantly lower score of language at the corrected age of 10 months and a significantly lower score of gross motor at the corrected age of 18 months (P<0.05). Compared with subgroup A of the deficiency group, subgroup B had a significantly higher score of adaptive ability at the corrected age of 10 months and significantly higher scores of adaptive ability and response ability at the corrected age of 18 months (P<0.05).

CONCLUSIONS

There is a significant difference in the level of 25(OH)D in umbilical cord blood in late preterm infants. Individualized vitamin D supplementation appears to be more effective for the treatment of vitamin D deficiency. Vitamin D level at birth and in early infancy has certain influence on neurobehavioral development.

Preterm Infants on Early Solid Foods and Vitamin D Status in the First Year of Life—A Secondary Outcome Analysis of a Randomized Controlled Trial

Preterm birth places infants at high risk for mineral and micronutrient deficiencies important for bone health. The aim of this study was to examine whether two timepoints for the introduction of solid foods in preterm infants have an impact on vitamin D status in the first year of life. This is a secondary outcome analysis of a prospective, randomized trial on very low birth weight (VLBW) infants, randomized to an early (10–12th week corrected age) or a late (16–18th week corrected age) complementary-feeding group. Vitamin D status was assessed by blood samples taken at 6 weeks, 6, and 12 months corrected age. In total, 177 infants were randomized (early group: n = 89, late group: n = 88). There was a tendency toward lower levels of serum 25-OH-vitamin D in the early group throughout the first year of life (p = not significant (n.s.)); no differences were detected in the other parameters. At 6 months corrected age, infants of the early group had a significantly higher incidence of vitamin D deficiency. The timepoint of the introduction of solid foods had no impact on the serum 25-OH-vitamin D levels and other parameters important for bone health but showed a tendency toward lower levels in the early-feeding group.