Maternal vitamin A administration and the fetal ductus arteriosus

Association of lower vitamin a levels in neonates and their mothers with increased risk of neonatal late-onset sepsis: A case-control study

BACKGROUND

In developing countries, neonatal sepsis is one of the major causes of mortality and morbidity. Vitamin A deficiency also affects the immune system severely and is associated with various neonatal infections. We aimed to compare maternal and neonatal vitamin A levels among neonates with and without late-onset sepsis.

MATERIAL AND METHODS

40 eligible infants were entered into this case-control study according to inclusion criteria. The case group included 20 term or near-term infants who had late-onset neonatal sepsis from three to seven days of life. The control group consisted of 20 term or near-term infants who were icteric hospitalized neonates without sepsis. Demographic, clinical and paraclinical features, as well as neonatal and maternal vitamin A levels, were compared between the two groups.

RESULTS

The average gestational age of the neonates was 37.1 ± 1.2, ranging from 35 to 39 days. There was a significant difference between the septic and non-septic groups in terms of white blood cell and neutrophil count, C-reactive protein, and neonatal and maternal vitamin A levels. A Spearman correlation analysis showed a significant direct correlation among maternal and neonatal vitamin A levels (correlation coefficient = 0.507; P-value = 0.001). Multivariate regression analysis showed that neonates' vitamin A level had a significant direct association with sepsis (OR: 0.541; P-value=0.017).

CONCLUSION

Our findings demonstrated the association of lower vitamin A levels in neonates and their mothers with an increased risk of late-onset sepsis, which emphasizes the importance of the consideration of vitamin A level evaluation and its appropriate neonatal and maternal supplementation.

Oral vitamin A supplementation in very low birth weight neonates: a randomized controlled trial

This randomized double-blind placebo-controlled trial evaluated the effects of early postnatal oral vitamin A supplementation (VAS) in 196 inborn very-low birth weight (VLBW) infants requiring respiratory support at 24 h of age. Eligible infants were randomized to receive aqueous syrup of vitamin A (10,000 IU of retinol/dose; n = 98) or placebo (n = 98) on alternate days for 28 days. Primary outcome variable was composite incidence of all-cause mortality and/or oxygen requirement for 28 days. Secondary outcome variables were safety/tolerability of VAS, serum retinol concentration at recruitment and day 28, duration of oxygen requirement and respiratory support and incidences of complications. On intention-to-treat analysis, composite incidence of all-cause mortality and oxygen requirement for 28 days was significantly lower in vitamin A group (relative risk (95% confidence interval), 0.440 (0.229-0.844); p < 0.05, number needed to benefit, 7). Requirement and duration of oxygen supplementation and non-invasive respiratory support, incidences of late-onset sepsis, patent ductus arteriosus, and duration of hospital stay were also significantly lower in vitamin A group. Serum retinol concentration improved significantly after VAS. No major adverse effect was observed.Conclusions: Early postnatal oral VAS was associated with better composite outcome of all-cause mortality and oxygen requirement without any major adverse effects.Clinical Trial Registration: Clinical Trials Registry of India (CTRI/2017/03/008131). What is Known: • Postnatal intramuscular vitamin A supplementation improves the survival, respiratory outcome and other morbidities in very low birth weight neonates without major adverse effects. • Limited studies on oral vitamin A supplementation did not document substantial benefits. What is New: • Early postnatal alternate-day oral vitamin A supplementation at the dose of 10,000 IU/dose for 28 days improves the composite outcome of death and oxygen requirement in very low birth weight neonates with respiratory distress • No major adverse effects were documented.

Vitamin A Deficiency Disorders in Children and Women

Vitamin A deficiency is an endemic nutrition problem throughout much of the developing world, especially affecting the health and survival of infants, young children, and pregnant and lactating women. These age and life-stage groups represent periods when both nutrition stress is high and diet likely to be chronically deficient in vitamin A. Approximately 127 million preschool-aged children and 7 million pregnant women are vitamin A deficient. Health consequences of vitamin A deficiency include mild to severe systemic effects on innate and acquired mechanisms of host resistance to infection and growth, increased burden of infectious morbidity, mild to severe (blinding) stages of xerophthalmia, and increased risk of mortality. These consequences are defined as vitamin A deficiency disorders (VADD). Globally, 4.4 million preschool children have xerophthalmia and 6 million mothers suffer night blindness during pregnancy. Both conditions are associated with increased risk of morbidity and mortality. While reductions of child mortality of 19–54% following vitamin A treatment have been widely reported, more recent work suggests that dosing newborns with vitamin A may, in some settings, lower infant mortality. Among women, one large trial has so far reported a ≥ 40% reduction in mortality related to pregnancy with weekly, low-dose vitamin A supplementation. Epidemiologic data on vitamin A deficiency disorders can be useful in planning, designing, and targeting interventions.

Differential response of human fetal smooth muscle cells from arterial duct to retinoid acid

AIM

The aim of the present study was to understand the role of retinoic acid (RA) in the development of isolated patent ductus arteriosus and the features of arterial duct-derived vascular smooth muscle cells (VSMC).

METHODS

The VSMC were isolated, and the biological characteristics and the response to RA were investigated in the arterial duct, aorta, and pulmonary artery VSMC from 6 human embryonic samples. Western blotting, immunostaining, and cell-based ELISA were employed to analyze the proliferation regulation of VSMC.

RESULTS

The VSMC from the arterial duct expressed proliferating cell nuclear antigen (PCNA) at a significantly lower rate than those from the aorta and pulmonary artery, but expressed a higher level of Bax and Bcl-2. The expression level of PCNA or Bcl-2 was associated with the embryonic age. The effects of RA on the VSMC from the arterial duct were quite different from those from the aorta and pulmonary artery. In arterial duct VSMC, RA stimulated PCNA expression, but such stimulation could be suppressed by CD2366, an antagonist of nuclear retinoid receptor activation. In aorta or pulmonary artery VSMC, the expression response of PCNA to RA was insignificant. The ratio of Bax/Bcl-2 decreased in arterial duct VSMC after RA treatment due to the significant inhibition of Bax expression.

CONCLUSION

The VSMC from the arterial duct possessed distinct biological behaviors. RA might be important in the development of ductus arteriosus VSMC.

Maternal vitamin A alters gene profiles and structural maturation of the rat ductus arteriosus

Retinoic acid (RA), a metabolite of vitamin A, has been proposed to regulate vascular remodeling and reactivity of the ductus arteriosus (DA). Using rat Affymetrix GeneChips, we found that a considerable number of genes in DA varied their expression levels in accordance with developmental mode: namely, preterm-, term-, and postnatal-dominant clusters. Among a total of 8,740 probe sets, maternal vitamin A administration (MVA) changed the expression levels of 91 genes (116 probe sets) >2.5-fold. About half of preterm- and term-dominant genes responded to MVA, whereas only 5% of postnatal-dominant genes responded to MVA, indicating that fetal-dominant genes were susceptible to RA signals. The expression levels of 51 genes in MVA-treated DA at preterm were similar to the expression levels in nontreated DA at term, indicating that the global gene profile at preterm resembled that of the control animal at term. We observed neointima formation in MVA-treated DA at preterm in accordance with upregulation of fibronectin and hyaluronic acid, whereas it was rarely observed in nontreated DA at preterm. Five fetal cardiac myofibrillar genes were also upregulated in MVA-treated in vivo DA, whereas they were developmentally downregulated in nontreated DA. The present study indicates that MVA-mediated alteration in gene profile was associated with early structural maturation of DA, although MVA-mediated maturation may differ from normal vascular remodeling of DA.

Vitamin A deficiency disorders in children and women

Vitamin A deficiency is an endemic nutrition problem throughout much of the developing world, especially affecting the health and survival of infants, young children, and pregnant and lactating women. These age and life-stage groups represent periods when both nutrition stress is high and diet likely to be chronically deficient in vitamin A. Approximately 127 million preschool-aged children and 7 million pregnant women are vitamin A deficient. Health consequences of vitamin A deficiency include mild to severe systemic effects on innate and acquired mechanisms of host resistance to infection and growth, increased burden of infectious morbidity, mild to severe (blinding) stages of xerophthalmia, and increased risk of mortality. These consequences are defined as vitamin A deficiency disorders (VADD). Globally, 4.4 million preschool children have xerophthalmia and 6 million mothers suffer night blindness during pregnancy. Both conditions are associated with increased risk of morbidity and mortality. While reductions of child mortality of 19-54% following vitamin A treatment have been widely reported, more recent work suggests that dosing newborns with vitamin A may, in some settings, lower infant mortality. Among women, one large trial has so far reported a > or = 40% reduction in mortality related to pregnancy with weekly, low-dose vitamin A supplementation. Epidemiologic data on vitamin A deficiency disorders can be useful in planning, designing, and targeting interventions.

Vitamin A and preterm infants: what we know, what we don't know, and what we need to know

Vitamin A is essential for optimal growth and development. In the developing world, vitamin A supplementation of the newborn infant reduces mortality. In the developed world, extremely preterm infants are born with low body stores of vitamin A and are at high risk of vitamin A deficiency. Optimal vitamin A supplementation for this population is not clearly defined, however, and, despite evidence of benefit, early vitamin A supplementation of extremely preterm infants is not uniformly practised in the United Kingdom. There is an urgent need for studies in preterm infants that include quantification of hepatic stores and functional assessment of vitamin A status as well as long term outcome.

Vitamin A and infancy. Biochemical, functional, and clinical aspects

Vitamin A is a very intriguing natural compound. The molecule not only has a complex array of physiological functions, but also represents the precursor of promising and powerful new pharmacological agents. Although several aspects of human retinol metabolism, including absorption and tissue delivery, have been clarified, the type and amounts of vitamin A derivatives that are intracellularly produced remain quite elusive. In addition, their precise function and targets still need to be identified. Retinoic acids, undoubtedly, play a major role in explaining activities of retinol, but, recently, a large number of physiological functions have been attributed to different retinoids and to vitamin A itself. One of the primary roles this vitamin plays is in embryogenesis. Almost all steps in organogenesis are controlled by retinoic acids, thus suggesting that retinol is necessary for proper development of embryonic tissues. These considerations point to the dramatic importance of a sufficient intake of vitamin A and explain the consequences if intake of retinol is deficient. However, hypervitaminosis A also has a number of remarkable negative consequences, which, in same cases, could be fatal. Thus, the use of large doses of retinol in the treatment of some human diseases and the use of megavitamin therapy for certain chronic disorders as well as the growing tendency toward vitamin faddism should alert physicians to the possibility of vitamin overdose.