Selenium and vitamin E concentrations in human milk and formula milk from Hungary

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.

Thyroidal and Extrathyroidal Requirements for Iodine and Selenium: A Combined Evolutionary and (Patho)Physiological Approach

Iodide is an antioxidant, oxidant and thyroid hormone constituent. Selenoproteins are needed for triiodothyronine synthesis, its deactivation and iodine release. They also protect thyroidal and extrathyroidal tissues from hydrogen peroxide used in the 'peroxidase partner system'. This system produces thyroid hormone and reactive iodine in exocrine glands to kill microbes. Exocrine glands recycle iodine and with high urinary clearance require constant dietary supply, unlike the thyroid. Disbalanced iodine-selenium explains relations between thyroid autoimmune disease (TAD) and cancer of thyroid and exocrine organs, notably stomach, breast, and prostate. Seafood is iodine unconstrained, but selenium constrained. Terrestrial food contains little iodine while selenium ranges from highly deficient to highly toxic. Iodine vs. TAD is U-shaped, but only low selenium relates to TAD. Oxidative stress from low selenium, and infection from disbalanced iodine-selenium, may generate cancer of thyroid and exocrine glands. Traditional Japanese diet resembles our ancient seashore-based diet and relates to aforementioned diseases. Adequate iodine might be in the milligram range but is toxic at low selenium. Optimal selenoprotein-P at 105 µg selenium/day agrees with Japanese intakes. Selenium upper limit may remain at 300-400 µg/day. Seafood combines iodine, selenium and other critical nutrients. It brings us back to the seashore diet that made us what we currently still are.

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.

Retinol and α-tocopherol in human milk and their relationship with dietary intake during lactation

Human milk is considered as an optimal nutrition source for neonates, and vitamins A and E improve oxidative stress in offspring through breast milk.

Vitamin E content and estimated need in German infant and follow-on formulas with and without long-chain polyunsaturated fatty acids (LC-PUFA) enrichment

Many formulas (FM) for infants are nowadays supplemented with LC-PUFA. Due to the susceptibility of LC-PUFA to peroxidation, a potential risk of oxidative stress must be considered. We analyzed the concentration of unsaturated fatty acids to calculate an estimated vitamin E need and the concentration of vitamin E as an important lipophilic antioxidant in LC-PUFA enriched (FM(+), n = 31) and not enriched (FM(-), n = 29) formulas as well as in breast milk (BM, n = 118). No differences were observed in the ratios of vitamin E content to estimated vitamin E need between FM(+) and FM(-). Ratios were consistently above the minimum value according to European law. FM showed similar or higher ratios than BM, except in a worst-case scenario where BM showed higher ratios than FM(+). Our results indicate adequate vitamin E content relative to unsaturated fatty acid content in present-day commercial formulas. Given that breast milk tends to contain higher ratios of vitamin E content to estimated vitamin E need than LC-PUFA enriched formulas (at least in a worst-case scenario), the potential effects of increasing vitamin E content in LC-PUFA enriched formulas should be explored.

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.

Concentrations of alpha- and gamma-tocopherols in human breast milk during the first months of lactation and in infant formulas

The aim of this study was to determine the concentrations of alpha- and gamma-tocopherols in human breast milk samples from different periods of lactation and to compare them with tocopherol content in commercially available formulas for infants at corresponding ages. The study included 93 breast milk samples obtained on the 2nd (colostrum, n = 17), 14th (n = 30), 30th (n = 27) and 90th day of lactation (n = 19), along with 90 samples of commercially available initial and follow-on infant formulas. Concentrations of tocopherols were determined using normal-phase high-performance liquid chromatography. Depending on the stage of lactation, human breast milk contained 2.07-9.99 mg L⁻¹ of alpha-tocopherol and 0.22-0.60 mg L⁻¹ of gamma-tocopherol. Breast milk concentrations of alpha-tocopherol decreased with the time of lactation, while significant differences in gamma-tocopherol concentration were observed only between the 14th and 30th day of lactation. There was no significant correlation between the dietary intake of vitamin E and its estimated breast milk concentration, also in women who declared vitamin supplementation. Compared with colostrum, infant formulas were characterised by significantly lower concentrations of alpha-tocopherol and vitamin E. This finding indicates the need of additional vitamin E supplementation of bottle-fed infants during the initial 2-3 days of life.