Enteral Low-Dose Vitamin A Supplementation in Preterm or Low Birth Weight Infants to Prevent Morbidity and Mortality: a Systematic Review and Meta-analysis

Objectives: To assess effects of enteral "low" dose (daily doses of ≤10 000 international unit) vitamin A supplementation compared with no vitamin A supplementation in human milk-fed preterm and low birth weight (LBW) infants.

Data Sources: Cochrane Central Register of Controlled Trials; Medline, Embase, Scopus, Web of Science, CINAHL from inception to 16 March 2021.

Study Selection: Randomized trials were screened. Primary outcomes were mortality, morbidity, growth, neurodevelopment. Secondary outcomes were feed intolerance and duration of hospitalization. We also assessed the dose and timing of vitamin A supplementation. Data were extracted and pooled with fixed and random-effects models.

Results: Four trials including 800 very LBW <1.5 kg or <32 weeks' gestation infants were found. At latest follow-up, we found little or no effect on: mortality, sepsis, bronchopulmonary dysplasia, retinopathy of prematurity, duration of hospitalisation. However, we found a increased level of serum retinol mean difference of 4.7 μg/ml (95% CI 1.2 to 8.2, I2 =0.00%, one trial, 36 participants,). Evidence ranged from very low to moderate certainty. There were no outcomes reported for length, head circumference or neurodevelopment.

Limitations: Heterogeneity and small sample size in the included studies.

Conclusions: Low-dose vitamin A increased serum retinol concentration among very LBW and very preterm infants but had no effect on other outcomes. More trials are needed to assess effects on clinical outcomes and to assess effects in infants 1.5 to 2.4 kg or 32 to 26 weeks' gestation.