Influence of prematurity and birth weight on the concentration of α-tocopherol in colostrum milk

Vitamin E concentration in breast milk in different periods of lactation: Meta-analysis

Objective

This study systematized information about vitamin E concentration in healthy breast milk during different stages of lactation in order to support the strategies of protecting postpartum women and infants.

Methods

Studies published before April 30th, 2021, which detected vitamin E concentration in breast milk of healthy women by High Performance Liquid Chromatography (HPLC) or Ultra High Performance Liquid Chromatographic (UHPLC), were evaluated. The databases of CNKI (Chinese), WanFang Data (Chinese), VIP (Chinese), PubMed, Cochrane Library, Web of Science and Embase were searched. The random effect models were used to conduct meta-analysis by the statistical software package Stata 14.0.

Results

In all 4,791 searched publications, 53 with full text were selected, which included 46 descriptive studies, 1 case-control study, 1 non-randomized controlled trial, and 5 randomized controlled trials. The pooled mean of vitamin E concentration was 10.57 mg α-TE/L (95%CI 8.94–12.20) in colostrum, 4.03 mg α-TE/L (95%CI 3.29–4.77) in transitional milk and 3.29 mg α-TE/L (95%CI 2.95–3.64) in mature milk. Subgroup analysis showed that vitamin E concentration of colostrum in Asian countries was lower than that in Western countries in colostrum and transitional milk.

Conclusions

Vitamin E concentration in breast milk decreased during lactation until the mature milk was produced. The vitamin E concentration of colostrum in Asian countries was evidently lower than that in Western countries. The vitamin E concentration in mature milk is similar in different regions. The concentration of vitamin E in breast milk started to be stable from about 2 to 3 weeks postpartum until 4 or 6 months postpartum, but it needs additional evidence to support.

Vitamin E and preterm infants

In evaluating vitamin E (VE) nutritional status of preterm infants, it is essential that any data should be compared with those of healthy term infants, and never with those of adults. Moreover, it should be evaluated in terms of gestational age (GA), not birth weight (BW), because placental transfer of most nutrients from mother to fetus is dependent on GA, not BW. Judging from the limited data during the last 75 years, there was no significant correlation between GA and VE concentrations in circulation or in the red blood cells (RBCs), leukocytes, and buccal mucosal cells. In addition, the oxidizability of polyunsaturated fatty acids (PUFAs) in plasma or RBCs, as targets for protection by VE chain-breaking ability, was lower in preterm infants. However, because of the minimal information available about hepatic VE levels, which is considered a key determinant of whole body VE status, the decision on whether VE status of preterm infants is comparable with that of term infants should be postponed. Clinical trials of VE supplementation in preterm infants were repeatedly undertaken to investigate whether VE reduces severity or inhibits development of several diseases specific to preterm infants, namely retinopathy of prematurity (ROP), bronchopulmonary dysplasia (BPD), and germinal matrix hemorrhage - intraventricular hemorrhage (GMH-IVH). Most of these trials resulted in a misfire, with a few exceptions for IVH prevention. However, almost all these studies were performed from 1980s to early 1990s, in the pre-surfactant era, and the study populations were composed of mid-preterm infants with GAs of approximately 30 weeks (wks). There is considerable difference in 'preterm infants' between the pre- and post-surfactant eras; modern neonatal medicine mainly treats preterm infants of 28 wks GA or less. Therefore, these results are difficult to apply in modern neonatal care. Before considering new trials of VE supplementation, we should fully understand modern neonatal medicine, especially the recent method of oxygen supplementation. Additionally, a deeper understanding of recent progress in pathophysiology and therapies for possible target diseases is necessary to decide whether VE administration is still worth re-challenging in modern neonatal intensive care units (NICUs). In this review, we present recent concepts and therapeutic trends in ROP, BPD, and GMH-IVH for those unfamiliar with neonatal medicine. Numerous studies have reported the possible involvement of reactive oxygen species (ROS)-induced damage in relation to supplemental oxygen use, inflammation, and immature antioxidant defense in the development of both BPD and ROP. Various antioxidants effectively prevented the exacerbation of BPD and ROP in animal models. In the future, VE should be re-attempted as a complementary factor in combination with various therapies for BPD, ROP, and GMH-IVH. Because VE is a natural and safe supplement, we are certain that it will attract attention again in preterm medicine.

Concentrations of Carotenoids and Tocopherols in Breast Milk from Urban Chinese Mothers and Their Associations with Maternal Characteristics: A Cross-Sectional Study

Milk composition remains the best estimate of infant requirements. The aims of this study were to quantify carotenoids and tocopherols in human milk from healthy Chinese mothers, and to explore their associations with lactation stage, region, socio-economic and obstetric characteristics, and dietary intake. Human milk was obtained from 509 healthy mothers, and concentrations of carotenoids and tocopherols were analyzed by Ultra High Performance Liquid Chromatography. The mothers’ socio-economic and obstetric characteristics and dietary intake through a single 24-h dietary recall were evaluated. The median concentrations (μg/100 mL) of each component of 0–4 days, 5–11 days, 12–30 days, 31–60 days, 61–120 days, and 121–240 days postpartum were respectively as follows: β-carotene 8.0, 2.8, 2.1, 1.7, 1.9, 1.8; β-cryptoxanthin 6.2, 3.4, 2.4, 1.7, 1.8, 2.1; lutein 5.7, 7.0, 2.2, 2.9, 2.8, 3.7; lycopene 6.3, 2.5, 1.8, 1.4, 1.4, 1.5; zeaxanthin 1.0, 1.4, 0.8, 0.8, 1.0, 1.1; α-tocopherol 645, 382, 239, 206, 212, 211; γ-tocopherol 68, 63, 70, 73, 68, 88. The levels of those components varied significantly among different lactation stages and presented regional differences. Associations of carotenoid contents with maternal education, delivery mode, and present body mass index were found in multivariate analyses. These results suggested that lactation stage, region, and socio-economic and obstetric factors were associated with human milk concentrations of carotenoids and tocopherols in healthy Chinese mothers.

Retinol and α-Tocopherol in the Breast Milk of Women after a High-Risk Pregnancy

BACKGROUND

There is scant information about whether, after a high-risk pregnancy, breast milk provides enough vitamins for assuring satisfactory bodily reserves in newborns.

OBJECTIVE

To comparatively evaluate, in women with high-risk and normal pregnancy, the concentration of retinol and α-tocopherol in breast milk.

METHODS

This cross-sectional, analytical study was evaluated with reverse-phase high-performance liquid chromatography (HPLC). Informed consent was signed by 95 mothers with a high-risk pregnancy and 32 mothers with a normal pregnancy. From the mothers with a high-risk pregnancy were obtained: 23 samples of colostrum, 24 of transitional milk, and 48 of mature milk. From the normal pregnancy group, 32 mature milk samples were collected. Pregestational Body Mass Index (BMI) and the gestational weight gain were noted. Models of logistic regression were constructed to identify the variables related to a low concentration of either retinol or α-tocopherol in breast milk.

RESULTS

The concentration of retinol and α-tocopherol in mature milk was 60 (interquartile range (IQR), 41-90) and 276 (103-450) μg/dL, respectively, for the high-risk pregnancy group, and 76 (65-91) and 673 (454-866) µg/dL, respectively, for the normal pregnancy group (p = 0.001). The concentration of retinol and α-tocopherol was similar in the subgroups of mothers with different disorders during gestation. A clear correlation was found between a greater pregestational weight and a lower concentration of retinol (Rho = -0.280, p = 0.006), and between α-tocopherol and retinol in all cases (Rho = 0.463, p = 0.001). Among women having a high-risk pregnancy, those delivering prematurely rather than carrying their pregnancy to term had a reduced concentration of retinol (54 (37-78) vs. 70 (49-106) µg/dL; p = 0.002) and a tendency to a lower concentration of α-tocopherol in breast milk (185 (75-410) vs. 339 (160-500) µg/dL; p = 0.053). Compared to mothers with a normal pregnancy, those with a high-risk pregnancy (whether carried to term or ending in preterm delivery) exhibited a reduced concentration of retinol in mature milk (p = 0.003), as well as a tendency to a lower concentration of α-tocopherol (p = 0.054).

CONCLUSION

Even though the women in the high-risk pregnancy group showed a deficiency of vitamins A and E in their breast milk, the unique biological benefits of this milk justify the promotion of breast feeding as the optimal method of nourishing neonates and infants. In these cases, it should be recommended that the woman increase her consumption of certain nutrients during pregnancy. Additionally, after childbirth mothers should consider the use of supplements to produce milk of adequate quality and thus meet the needs of the baby and prevent any deficiency in micronutrients.

Maternal supplementation with a megadose of vitamin A reduces colostrum level of α-tocopherol: a randomised controlled trial

BACKGROUND

Maternal supplementation with vitamin A is one of the strategies for controlling its deficiency in the mother-child dyad, although studies with animals showed that supplementation with high doses of vitamin A reduces the levels of α-tocopherol (vitamin E) in the mother's serum and milk. The objective of the present study was to assess the influence of maternal supplementation with vitamin A on the concentration of retinol and α-tocopherol in human milk.

METHODS

Healthy puerperal women were randomly distributed into a control group (n = 44) and a supplemented group (n = 44). Blood and colostrum samples were collected after delivery, and mature milk samples were collected 30 days later. The supplemented group received 200 000 IU of retinyl palmitate after the first colostrum collection. The retinol and α-tocopherol levels in the samples were determined by high-performance liquid chromatography.

RESULTS

The mean (SD) retinol and α-tocopherol levels in the maternal serum were considered adequate at 46.4 (15.9) and 1023.6 (380.4) μg dL(-1) , respectively. The colostrum retinol levels of the supplemented group increased significantly 24 h after the intervention (P < 0.001). However, the retinol levels in the mature milk of both groups did not differ (P > 0.05). Moreover, after maternal supplementation with vitamin A, the colostrum α-tocopherol level decreased by 16.4%, which is a significant reduction (P < 0.05). However, vitamin A supplementation did not affect the α-tocopherol level of mature milk (P > 0.05).

CONCLUSIONS

Maternal supplementation with high doses of vitamin A increased the colostrum level of this nutrient but reduced the bioavailability of α-tocopherol, which may harm the newborn's health because newborns have limited vitamin E reserves.

Retinol and Alpha-tocopherol in the Colostrum of Lactating Tunisian Women Delivering Prematurely: Associations with Maternal Characteristics

BACKGROUND

This study aims to assess vitamin A and E concentrations in the premature colostrum of lactating Tunisian women and to identify maternal characteristics that may affect these concentrations.

METHODS

Human colostrum was obtained from 105 mothers who gave birth prematurely in the Centre for Maternity and Neonatology of Tunis (Tunisia). Retinol and alpha-tocopherol were analyzed in the colostrum and in plasma by high-performance liquid chromatography.

RESULTS

Retinol and alpha-tocopherol concentrations were 57.5 ± 50.1 μg/dL and 1222 ± 772 μg/dL in the colostrum, respectively, and 51.7 ± 20.0 μg/dL and 1351 ± 772 μg/dL in plasma, respectively. Concentrations of each vitamin in the colostrum were positively correlated with their respective concentrations in plasma (r = 0.415, p = 0.001 for retinol and r = 0.392, p = 0.003 for alpha-tocopherol). In multivariate analysis, colostrum vitamin A was associated with plasma vitamin A and preeclampsia, while colostrum vitamin E was associated with plasma vitamin E, gestational age, and preeclampsia.

CONCLUSION

In Tunisian women, colostrum vitamin A and E levels are close to the average values reported in the literature. The levels are too low to cover the needs of very low birth weight (VLBW) infants, particularly in women with plasma vitamin deficiencies, preeclampsia, or very premature delivery. Given the undeniable beneficial effects of human colostrum, whenever feasible, VLBW infants should be fed colostrum. Infant vitamin A and E requirements should be met by milk fortification or supplementation.

α-Tocopherol in breast milk of women with preterm delivery after a single postpartum oral dose of vitamin E

We evaluated the effect of maternal vitamin E supplementation on the α-tocopherol concentrations of colostrum, transitional milk and mature milk of women who had given birth prematurely. This longitudinal randomised-controlled trial divided eighty-nine women into two groups: a control group and a supplemented group. Blood and breast milk were collected from all the participants after delivery. Next, each woman in the supplemented group received 400 IU of RRR-α-tocopheryl acetate. Further breast milk samples were collected 24 h after the first collection, as well as 7 and 30 d after delivery. α-Tocopherol concentrations were determined by HPLC. The baseline α-tocopherol concentrations in the maternal serum of the two groups were similar: 1159·8 (sd 292·4) μg/dl (27·0 (SD 6·8) μmol/l) for the control group and 1128·3 (sd 407·2) μg/dl (26·2 (SD 9·5) μmol/l) for the supplemented group. None of the women was vitamin E deficient. Breast milk α-tocopherol concentrations increased by 60 % 24 h after supplementation in the intervention group and did not increase at all in the control group. α-Tocopherol concentration of the transitional milk in the supplemented group was 35 % higher compared with the control group. α-Tocopherol concentrations of the mature milk in both groups were similar. Maternal supplementation with 400 IU of RRR-α-tocopherol increased the vitamin E concentrations of the colostrum and transitional milk, but not of the mature milk. This study presents relevant information for the design of strategies to prevent and combat vitamin E deficiency in the risk group of preterm infants.

Alpha-Tocopherol Concentration in Colostrum and Serum of Women With Premature Labor

OBJECTIVE

The aim of the study was to evaluate and compare the levels of alpha-tocopherol in colostrum milk and serum of mothers with premature birth, classified as severe prematurity and moderate prematurity.

METHODS

Cross-sectional study with 65 women, 18 births classified as severe prematurity (<32 weeks of gestation) and 47 as moderate prematurity (≥32 weeks of gestation). The study only included mothers without any conditions associated with pregnancy and who had a single conception without any malformation. Samples of serum and colostrum were collected during fasting in the immediate postpartum, and alpha-tocopherol was analyzed by high-performance liquid chromatography. To determine the biochemical nutritional status of vitamin E, a serum cutoff (11.6 μmol/L) was adopted. The Student t test for independent variables compared the average concentrations of alpha-tocopherol in serum and colostrum among prematurity groups. Differences were considered significant when P < 0.05.

RESULTS

The alpha-tocopherol concentrations in colostrum were similar in both groups, being 34.5 ± 20.2 μmol/L for women with severe prematurity and 35.1 ± 16.3 μmol/L for moderate prematurity. For the serum of puerperal women with severe prematurity, alpha-tocopherol concentration was, however, lower than in women with moderate prematurity, 22.2 ± 4.4 μmol/L versus 27.1 ± 8.6 μmol/L (P < 0.05). The serum levels of alpha-tocopherol indicated nutritional risk at 5.6% (n = 1) of women with severe prematurity and 4.3% (n = 2) for those with moderate prematurity.

CONCLUSIONS

Severe prematurity affected the levels of alpha-tocopherol in maternal serum; however, the level of prematurity did not change the concentration of vitamin E in colostrum.

Vitamin E concentration in human milk and associated factors: a literature review

OBJECTIVE

To systematize information about vitamin E concentration in human milk and the variables associated with this composition in order to find possible causes of deficiency, supporting strategies to prevent it in postpartum women and infants.

SOURCE

Studies published between 2004 and 2014 that assayed alpha-tocopherol in human milk of healthy women by high performance liquid chromatography were evaluated. The keywords used were "vitamin E", "alpha-tocopherol", "milk, human", "lactation", and equivalents in Portuguese, in the BIREME, CAPES, PubMed, SciELO, ISI Web of Knowledge, HighWire Press, Ingenta, and Brazilian Digital Library of Theses and Dissertations databases.

SUMMARY OF THE FINDINGS

Of the 41 publications found on the subject, 25 whose full text was available and met the inclusion criteria were selected. The alpha-tocopherol concentrations found in milk were similar in most populations studied. The variable phase of lactation was shown to influence vitamin E content in milk, which is reduced until the mature milk appears. Maternal variables parity, anthropometric nutritional status, socioeconomic status, and habitual dietary intake did not appear to affect the alpha-tocopherol levels in milk. However, the influence of the variables maternal age, gestational age, biochemical nutritional status in alpha-tocopherol, and maternal supplementation with vitamin E had conflicting results in the literature.

CONCLUSION

Alpha-tocopherol concentration in milk decreases during lactation, until the mature milk appears. To confirm the influence of some maternal and child variables on milk vitamin E content, further studies with adequate design are needed.