Update on Vitamin E and Its Potential Role in Preventing or Treating Bronchopulmonary Dysplasia

Abstract

Vitamin E is obtained only through the diet and has a number of important biological activities, including functioning as an antioxidant. Evidence that free radicals may contribute to pathological processes such as bronchopulmonary dysplasia (BPD), a disease of prematurity associated with increased lung injury, inflammation and oxidative stress, led to trials of the antioxidant vitamin E (α-tocopherol) to prevent BPD with variable results. These trials were all conducted at supraphysiologic doses and 2 of these trials utilized a formulation containing a potentially harmful excipient. Since 1991, when the last of these trials was conducted, both neonatal management strategies for minimizing oxygen and ventilator-related lung injury and our understanding of vitamin E isoforms in respiratory health have advanced substantially. It is now known that there are differences between the effects of vitamin E isoforms α-tocopherol and γ-tocopherol on the development of respiratory morbidity and inflammation. What is not known is whether improvements in physiologic concentrations of individual or combinations of vitamin E isoforms during pregnancy or following preterm birth might prevent or reduce BPD development. The answers to these questions require adequately powered studies targeting pregnant women at risk of preterm birth or their premature infants immediately following birth, especially in certain subgroups that are at increased risk of vitamin E deficiency (e.g., smokers). The objective of this review is to compile, update, and interpret what is known about vitamin E isoforms and BPD since these first studies were conducted, and suggest future research directions.

Comparative two time-point proteome analysis of the plasma from preterm infants with and without bronchopulmonary dysplasia

“…Unfortunately, until now, clinical studies aimed at reducing the frequency of BPD by the supplementation of vitamin E have not brought the expected favorable results [33]. Our finding may support the idea of re-reviewing the hitherto knowledge about the connection between vitamin E and BPD, and the possible methods of preventing or alleviating this severe complication of prematurity, by obtaining the adequate level of appropriate isoform of this antioxidant in the maternal/infant organism [34]. We also believe that it is worth investigating whether the lower level of vitamin E carrier proteins might decrease the bioavailability of vitamin E, despite supplementation.…”

Lactational changes of fatty acids and fat-soluble antioxidants in human milk from healthy Chinese mothers

“…Polarity may be involved because α-tocopherol possessing lower polarity indicated bigger decreases than γ-tocopherol over lactation. As positive roles have been attributed to α-tocopherol in bronchopulmonary dysplasia and childhood asthma, γ-tocopherol indicates more harmful effects through pro-inflammatory properties than its antioxidant benefits (19) . However, infant formulas, calculated by the published data, provide a much lower ratio of α-:γ-tocopherol as (0•68-2•51):1 (4,10) .…”

“…Other vitamin E isoforms were less investigated, but concerns have arisen that an increasing number of foods and formulas deliver much higher γ-tocopherol than α-tocopherol (4,16,17) . γ-Tocopherol also decreases lipid peroxidation (weaker than α-tocopherol) and neutrophilic inflammation (stronger than α-tocopherol), but it can promote type 2 inflammation (18,19) . The latest early life study in both Nigerian and American maternal-neonatal dyads reported the association between decreased circulating α-:γ-tocopherol and negative birth outcomes such as Caesarian sections (20) .…”

Nutrients and Microbiota in Lung Diseases of Prematurity: The Placenta-Gut-Lung Triangle

“…However, none of these trials were conducted after 1991, and the nature and epidemiology of BPD has since profoundly evolved. No human trial has investigated antenatal supplementation and neonatal outcomes so far (for review, see [61]).…”