Vitamina e

Vitamin E: maternal concentrations are associated with fetal growth1,2,3
Theresa O Scholl, Xinhua Chen, Melissa Sims and T Peter Stein
1 From the Departments of Obstetrics and Gynecology (TOS and XC) and Surgery (MS and TPS), University of Medicine and Dentistry of New Jersey School of Osteopathic Medicine, Stratford, NJ
2 Supported by the National Institutes of Health (HD38329).
3 Addressreprint requests to TO Scholl, UMDNJ-SOM, Department of Ob/Gyn, Science Center, Suite 390, Stratford, NJ 08104. E-mail: scholl@umdnj.edu.
| |   ABSTRACT |

 
Background: Few data exist on the effects of the 2 most abundant isomers of vitamin E ([pic]- and [pic]-tocopherols) onfetal growth.
Objective: We measured maternal plasma concentrations of [pic]- and [pic]-tocopherols and examined their relation with measures of fetal growth. We also examined the relation, controlled for associated maternal factors, of diet and supplement use to tocopherol concentrations at week 28 of gestation.
Design: A cohort of 1231 gravid women from Camden, NJ, was studied from entry to care(16.0 ± 0.15 wk gestation); plasma tocopherol concentrations were measured at entry and at week 28.
Results: Plasma concentrations of [pic]-tocopherol at entry and at week 28 were positively related to increased fetal growth (birth weight for gestation), a decreased risk of small-for-gestational-age births, and an increased risk of large-for-gestational-age births. Concentration of[pic]-tocopherol at week 28 was positively related to use of prenatal multivitamins and dietary intake of vitamin E; concentration of [pic]-tocopherol was related positively to dietary fat intake and negatively to multivitamin use.
Conclusion: Early and late circulating concentrations of [pic]-tocopherol are positively associated with fetal growth.
Key Words: Birth weight • fetal growth • small forgestational age • large for gestational age • vitamin E • antioxidants • [pic]-tocopherol • [pic]-tocopherol • multivitamins • maternal nutrition • pregnancy

|[pic] |   INTRODUCTION |

 
Emerging evidence suggests that during pregnancy oxidative damage to DNA, protein, and lipids may beassociated with reduced birth weight and increased risks of outcomes such as low birth weight, preterm delivery, and preeclampsia (1-3). Risk may, however, depend on the mother's antioxidant status (1, 3) which potentially protects the maternal-fetal unit, thus increasing intrauterine growth and infant weight at birth.
Antioxidants scavenge free radicals and buffer the effects of prooxidants by reducingoxidative stress and preventing oxidative damage. Antioxidants are produced endogenously by the body or are consumed as part of the diet. Vitamin E is a lipid-soluble chain-breaking antioxidant that is dietary in origin. Of the 8 isomers of vitamin E that occur naturally, [pic]-tocopherol is the most abundant in plasma, cell membranes, other human tissues, and nutritional supplements, whereas[pic]-tocopherol is the primary form found in the human diet. The concentration of [pic]-tocopherol in plasma and tissues is 4–5-fold lower than [pic]-tocopherol (4).
In addition to its antioxidant actions, an effect of vitamin E that is of potential consequence for the course and outcome of pregnancy involves prostacyclin (4). Vitamin E enhances the release of prostacyclin, a metabolite ofarachadonic acid that inhibits platelet aggregation, quiets uterine contractility, and increases vasodilation (4). Thus, it is plausible that circulating concentrations of [pic]- and [pic]-tocopherols could be associated with altered fetal growth by increased blood flow and nutrient supply to the fetus.
The influence of [pic]-tocopherol on fetal growth has been examined only rarely; as far as we are...