Breast Milk Retinol Research Articles

A Correlation Study of Plasma and Breast Milk Retinol Concentrations in Breastfeeding Women in China.

Retinol in breast milk is related to plasma concentration among breastfeeding women, but the linear or curvilinear relationships between the two remains unclear. We conducted a cross-sectional study in 403 Chinese breastfeeding women at 42 ± 7 days postpartum. Plasma and breast milk samples were assayed using high performance liquid chromatography to determine the concentration of retinol. Partial Spearman correlation and multivariable fractional polynomial regression were used to examine the relationships between the two retinol concentrations and between plasma retinol concentration and milk-to-plasma (M/P) retinol. The median (interquartile range, IQR) of the retinol concentration in the plasma was 1.39 (1.21, 1.63) μmol/L and 1.15 (0.83, 1.49) μmol/L in the breast milk, respectively. The partial correlation coefficient between them was 0.17 (p < 0.01). A linear relationship was observed with an adjusted regression coefficient of 0.34 (95% CI: 0.19, 0.49). The relationship between the plasma retinol and M/P ratio was nonlinear and segmented at 1.00 μmol/L of plasma retinol. The regression coefficients, below and above the segmented point, were -1.69 (95% CI: -2.75, -0.62) and -0.29 (95% CI: -0.42, -0.16), respectively. Plasma and breast milk retinol were positively correlated, whereas women with a low concentration of plasma retinol showed a stronger capacity of transferring retinol to breast milk.

Assessment of vitamin A levels in breast milk and serum of lactating mothers in Southeast Nigeria

Background: Vitamin A (VA) is an essential micronutrient critical to human health, infants rely on their mother’s breast milk for sufficient supply. This makes the maternal diet a crucial source of VA for infant growth and development. Aims: This study aimed to assess maternal VA status by assessing serum and breast milk retinol concentrations as well as dietary intake in nursing mothers. Subjects and Methods: A clinic-based cross-sectional study, conducted in Awka, south-east Nigeria, was used to assess 127 lactating women at one to 24 months post-partum. Blood and breast milk samples were obtained from each participant in a fasted state while dietary intake was assessed via an interviewer-administered semi-structured food frequency questionnaire. Retinol concentration was analyzed by spectrophotometry. Descriptive statistics were used to summarize the data while Spearman rank correlation analysis was used to determine associations between breast milk and serum retinol concentrations and study variables. Results: The mean retinol concentration in the serum of the women was a borderline value of 0.75 ± 0.64 µmol/L while the mean retinol concentration in breast milk was 0.99 ± 0.71 µmol/L. Further, the mean milk fat content was 56.18 ± 32.32 g/L while the mean milk retinol to fat ratio was 0.027 ± 0.044 µmol/g. Maternal diet consisted of a preference for provitamin A foods with low bioavailability. The mean retinol concentration in breast milk increased with time post-partum. There was no statistically significant relationship found between the frequency of consumption of most foods and the concentration of retinol in breast milk. Conclusion: The evidence of VA deficiency highlights the need for screening and nutrition education of breastfeeding mothers during ante- and post-natal visits. Keywords: Human milk, serum, vitamin A, maternal diet.

Breast Milk Retinol Concentrations Reflect Total Liver Vitamin A Reserves and Dietary Exposure in Thai Lactating Women from Urban and Rural Areas

Measuring vitamin A (VA) status during lactation is required to inform dietary recommendations. Limited data exist on VA stores in women. Our objective was to assess VA status in lactating Thai women by measuring total body VA stores (TBSs), serum and breast milk retinol concentrations, and dietary intake. Lactating women (n=94), 6-8 wk postpartum, were enrolled from rural (Ayutthaya) and urban (Bangkok) areas. TBSs were measured by the 13C-retinol isotope dilution (RID) technique using 2.0 μmol 13C-retinyl acetate and a single blood sample 14 d post-dose. Natural 13C-enrichment was determined in nonenrolled women (n=11). Estimated total liver VA reserves (TLRs) were determined using assumptions for lactation. Serum, foremilk, and hindmilk samples were analyzed for retinol by HPLC. Dietary VA intake was assessed by FFQ and 24-h dietary recalls for 3 d. Multiple regression and Pearson correlation were used to evaluate relations. Median VA intakes were 51.8% of 2003 Thai daily recommendations for lactating women, with the majority from animal-source foods. Many women in Ayutthaya consumed liver weekly. Considering TLRs as 50% TBS, 20% and 11% of mothers in Ayutthaya and Bangkok, respectively, showed deficient reserves (≤0.10μmol retinol/g). Median (quartile 1, quartile 3) serum [1.58 (1.34, 1.91) and 1.52 (1.30, 1.70) μmol/L] and milk [1.88 (1.29, 2.95) and 1.74 (0.96, 2.26) μmol/L] retinol in Ayutthaya and Bangkok, respectively, were normal. Women with deficient TLRs showed low milk retinol concentrations (≤1.0μmol/L) and consumed less dietary VA, especially from animal-source foods. Breast milk retinol concentrations, especially hindmilk, demonstrated strong correlation with TBSs and TLRs estimated from the RID test. Approximately 15% of Thai lactating women had deficient TLRs. Breast milk retinol concentrations in conjunction with dietary intake records show potential to screen mothers at risk of VA deficiency to guide interventions.The Thai Clinical Trials Registry number is TCTR20160824001 for the work in Thailand.

Breast Milk Retinol Levels after Vitamin A Supplementation at Different Postpartum Amounts and Intervals.

Maternal vitamin A (VA) supplementation in risk areas for Vitamin A deficiency (VAD) was launched to improve the level of this nutrient in nursing mothers and in their breast milk. This longitudinal and randomized study aimed to evaluate the levels of retinol in breast milk after supplementation with VA in varying amounts (200,000 IU or 400,000 IU) and different postpartum intervals. Women were distributed into four intervention groups and given a single 200,000 IU postnatal dosage of VA at time 0 h (postnatal morning) (G200 0H); a single 200,000 IU dosage of VA in week four (G200 4W); 200,000 IU of VA at time 0 h + 200,000 IU of VA 24 h after the first supplementation (G400 24H); and 200,000 IU of VA at time 0 h + 200,000 IU of VA one week after the first supplementation (G400 1W). Breast milk samples were collected over a 12-week period (0 h, 24 h and 1, 4, 12 weeks post-natal). Retinol levels were determined by high-performance liquid chromatography. The Generalized Estimated Equation (GEE) assessed the different retinol levels. The G200 (0H), G400 (24H), and G400 (1W) groups presented higher retinol levels at 24 h than the G200 (4W) group (p < 0.001). The retinol levels of all groups were similar at times 1, 4 and 12 weeks after delivery (p > 0.05). Maternal VA supplementation increased retinol levels in the colostrum. Different supplementation dosages or postpartum administration times did not result in added benefit to retinol levels in mature breast milk.

Carotenoids and Vitamin A in Breastmilk of Hong Kong Lactating Mothers and Their Relationships with Maternal Diet.

Carotenoids and vitamin A are nutrients crucial to infants’ development. To date, there is limited data on their availability in breastmilk and the associated dietary factors, especially in Hong Kong, where people follow a westernized Chinese diet. This study determined the selected breastmilk’s carotenoid and vitamin A (retinol) contents by ultraperformance liquid chromatography with photodiode detection (UPLC-PDA) and the dietary intakes by three-day food records in 87 Hong Kong lactating mothers, who were grouped into tertiles based on their daily carotenoid intake. Low vitamin A intake (530.2 ± 34.2 µg RAE/day) and breastmilk retinol level (1013.4 ± 36.8 nmol/L) were reported in our participants, suggesting a poor vitamin A status of the lactating participants having relatively higher socioeconomic status in Hong Kong. Mothers in the highest tertile (T3) had higher breastmilk carotenoid levels than those in the lowest (T1) (p < 0.05). There were significant associations between maternal carotenoid intakes and breastmilk lutein levels in the linear regression models (p < 0.05) regardless of dietary supplement intake. Furthermore, maternal dark green vegetable intakes were associated with breastmilk retinol, lutein, and β-carotene levels. These findings can serve as dietary references for lactating mothers to enhance breastmilk carotenoid and vitamin A contents for the benefits of child growth and development.

Effect of Vitamin A Supplementation, Cooking Oil Fortification, and Nutrition Education to Postpartum Mother on Breast Milk Retinol Levels

AIM: The study aims to determine the effect of two forms of Vitamin A supplementation (dose of 2 × 200 000 IU and dose of 1 × 200 000 IU), Vitamin A fortified cooking oil and nutritional education on retinol levels of breast milk. METHODS: A quasi-experiment design was used in this study with a total of 129 subjects divided into four groups; Group A (given 2 capsule of Vitamin A), Group B (given 1 capsule of Vitamin A), Group C (given cooking oil fortification), and Group D (given nutritional education). Retinol levels of the breast milk were measured 3 times (before, during, and after intervention). RESULTS: There were no differences in subject characteristics in terms of age, education, occupation, parity, and nutritional status between intervention groups (p &gt; 0.05). The average of breast milk retinol levels was 52.15 μg/dl at the beginning. At the end of the measurement, the average decrease in breast milk retinol levels was higher in Group D (−27.2 μg/dl), and the lowest was in Group C (−9.9 μg/dl). The results of statistical tests showed that there was no difference in breast milk retinol levels between intervention groups in before, during, and after the intervention (p &gt; 0.05). CONCLUSIONS: Fortified cooking oil and Vitamin A supplementation (1 × 200 000 IU) tend to maintain normal levels of retinol in breast milk compared to Vitamin A supplementation (2 × 200 000 IU) and nutrition education.

Impact of Maternal Daily Oral Low-Dose Vitamin A Supplementation on the Mother-Infant Pair: A Randomised Placebo-Controlled Trial in China.

Background: The nutritional status of vitamin A in lactating mothers and infants is still not optimistic. Due to the dietary habits and dietary restrictions of postpartum customs in China, vitamin A supplementation has been advocated as a potential strategy to improve vitamin A status of lactating mothers with inadequate dietary vitamin A intake. Existing clinical trials are limited to single or double high-dose maternal administrations. However, in China, vitamin A supplements are readily available in the form of daily oral low-dose supplements, and the effect of these is unknown. This study aimed to evaluate the effects of daily oral low-dose vitamin A supplementation on the retinol levels in the serum and breast milk of lactating mothers and the health status of infants in China. Methods: Lactating mothers who met the inclusion criteria and planned to continue exclusive breastfeeding were randomly assigned to receive either daily oral vitamin A and D drops (one soft capsule of 1800 IU vitamin A and 600 IU vitamin D2), or a matching placebo for 2 months. Before and after the intervention, dietary intake was investigated by instant photography, and the retinol concentration in maternal serum and breast milk was determined by ultra-high performance liquid chromatography-tandem mass spectrometry. During the trial, the health status of infants was diagnosed by a paediatrician or reported by lactating mothers. A total of 245 participants completed the study, with 117 in the supplementation group and 128 in the control group. Results: After the 2-month intervention, maternal serum retinol concentrations increased in the supplementation group with no change in the control group. Although breast milk retinol concentrations decreased significantly in both groups, the decrease in the supplementation group was significantly lower than that in the control group. However, maternal vitamin A supplementation was not associated with a lower risk of infant febrile illness, respiratory tract infection, diarrhoea, and eczema. Conclusions: Daily oral low-dose vitamin A supplementation is helpful in improving maternal vitamin A status, despite having no effect on infant health status through breast milk.

Breast Milk Retinol Is Negatively Associated With General Parameters of Obesity in Lactating Women

ObjectivesTo evaluate the correlation between breast milk retinol concentration and general parameters of obesity in lactating women. MethodsThis is a cross-sectional study design. Participants were 21 lactating women between 54.2 ± 2.35 d postpartum, and who declared exclusive or predominant breastfeeding practices. A casual sample of breast milk (∼3 mL) was collected and breast milk retinol was analyzed by HPLC. General anthropometric measurements (weight, height, waist and hip circumference) were performed. The Spearman test was used to assess the correlation between the variables. ResultsParticipating lactating women were 19–34 y of age. Breast milk retinol concentration was 1.84 ± 0.84 μmol/L; 38.1% (n = 8) of lactating women had low breast milk concentration of vitamin A (< 1.05 μmol/L). Body Mass Index (BMI) was 26.7 ± 4.32; 33.3% of the women had a normal BMI, 52.4% were overweight and 14.3% were obese. Waist (83.2 ± 8.81 cm) and hip circumference (104 ± 9.35 cm), were also recorded. BMI (r = –0.551, p = 0.010), waist (r = –0.480, p = 0.028) and hip circumference (r = –0.484, p = 0.030) negatively correlated with retinol concentrations in breast milk. ConclusionsIn this group of women, breast milk retinol concentration was lower in women with higher BMI, waist and hip circumference. Funding SourcesJA-P received a fellowship from the Mexican National Research and Technology Council.

Simulated Impact of Vitamin A Fortified Sugar on Dietary Adequacy and Association of Usual Sugar Intake With Plasma and Breast Milk Retinol Among Lactating Women in Rural Zambia

ObjectivesZambia introduced mandatory sugar fortification with vitamin A (VA) in 1998; however, regulatory monitoring and evaluation have been limited. We studied the contribution of VA-fortified sugar intake to dietary adequacy, and examined associations between usual sugar and VA intakes with plasma and breast milk retinol concentrations in lactating women in rural Zambia. MethodsWe conducted three 24-h dietary recalls among each of 255 lactating women enrolled in a randomized trial, at the time of baseline venous blood and breast milk collection. We measured retinol in biospecimens using high-performance liquid chromatography. We simulated VA intake under various sugar fortification scenarios: 3.1 and 8.8 mg/kg (measured median fortification levels of VA in sugar from previous studies), 10 mg/kg (minimum legal requirement) and 15 mg/kg (minimum legal requirement at factory level). Usual intake distributions, prevalence of inadequate VA intake (< Estimated Average Requirement of 900 μg RAE/d) and prevalence of retinol intake above the tolerable upper intake level (UL, >3000 μg/d) for each scenario were estimated using the National Cancer Institute (NCI) method. We applied the NCI’s “bivariate model” as a regression calibration tool to examine associations of usual intake of sugar and dietary VA with plasma and breast milk retinol concentrations. ResultsIn the absence of sugar fortification, the prevalence of VA inadequacy was predicted to be 83% (SE: 6). Fortification of sugar with VA at 3.1 mg/kg, 8.8 mg/kg, 10 mg/kg and 15 mg/kg would reduce the prevalence of VA inadequacy by 7 (SE:6), 24 (SE:14), 30 (SE:15) and 47 (SE:18) percentage points, respectively, without increasing the risk of retinol intake above the UL. Usual sugar intake and usual VA intake were not associated with plasma retinol or breastmilk retinol concentrations. ConclusionsThe sugar fortification program has the potential to reduce dietary VA inadequacy, but the impact is likely to be limited if actual fortification levels are lower than mandated levels. Even if target fortification levels are achieved (10 mg/kg), sugar fortification alone is unlikely to eliminate dietary VA inadequacy among lactating women in rural Zambia. Funding SourcesHarvestPlus and the Sight and Life Global Nutrition Research Institute at Johns Hopkins University.

Biofortified and fortified maize consumption reduces prevalence of low milk retinol, but does not increase vitamin A stores of breastfeeding Zambian infants with adequate reserves: a randomized controlled trial

Replacement of conventional staples with biofortified or industrially fortified staples in household diets may increase maternal breast milk retinol content and vitamin A intakes from complementary foods, improving infant total body stores (TBS) of vitamin A. To determine whether biofortified or industrially fortified maize consumption by Zambian women and their breastfeeding infants could improve milk retinol concentration and infant TBS. We randomly assigned 255 lactating women and their 9-mo-old infants to a 90-d intervention providing 0 µg retinol equivalents (RE)/d as conventional maize or ∼315 µg RE/d to mothers and ∼55 µg RE/d to infants as provitamin A carotenoid-biofortified maize or retinyl palmitate-fortified maize. Outcomes were TBS, measured by retinol isotope dilution in infants (primary), and breast milk retinol, measured by HPLC in women (secondary). The intervention groups were comparable at baseline. Loss to follow-up was 10% (n=230 mother-infant pairs). Women consumed 92% of the intended 287 g/d and infants consumed 82% of the intended 50 g/d maize. The baseline geometric mean (GM) milk retinol concentration was 1.57 μmol/L (95% CI: 1.45, 1.69 μmol/L), and 24% of women had milk retinol<1.05 μmol/L. While mean milk retinol did not change in the biofortified arm (β: 0.11; 95% CI: -0.02, 0.24), the intervention reduced low milk retinol (RR:0.42; 95% CI: 0.21, 0.85). Fortified maize increased mean milk retinol (β: 0.17; 95% CI: 0.04, 0.30) and reduced the prevalence of low milk retinol (RR:0.46; 95% CI: 0.25, 0.82). The baseline GM TBS was 178 μmol (95% CI: 166, 191 μmol). This increased by 24 µmol (± 136) over the 90-d intervention period, irrespective of treatment group. Both biofortified and fortified maize consumption improved milk retinol concentration. This did not translate into greater infant TBS, most likely due to adequate TBS at baseline. This trial was registered at clinicaltrials.gov as NCT02804490.

Effect of vitamin A, calcium and vitamin D fortification and supplementation on nutritional status of women: an overview of systematic reviews

BackgroundMicronutrient deficiency affects the health and development of vulnerable population such as children and pregnant women. Measures such as fortification of food and supplementation have been implemented to prevent or control deficiencies related to micronutrients.ObjectiveTo assess the effect of vitamin A, vitamin D, and calcium fortification and supplementation on nutritional status of women in reproductive age group. To assess the toxicities and adverse events related to intervention.MethodologySystematic reviews including RCTs on women of reproductive age group provided with vitamin A, vitamin D, and calcium supplementation or fortified food were included, to report all malnutrition-related outcomes due to deficiency of the abovementioned micronutrients. The Cochrane Database of Systematic Reviews, EPPI Centre, Campbell Collaboration, PubMed, Web of Science, and Scopus were searched electronically for English language publications, until 31 March 2018. Hand searching of the articles was done from the Journal of Food Science and Technology. Two independent reviewers selected the systematic reviews, extracted data, and assessed for the quality.ResultsA total of 16 systematic reviews were included in narrative synthesis. Supplementation of vitamin A was reported to result in increased maternal serum retinol concentrations and increased breast milk retinol concentration. It reduced the risk of anemia (Hb < 11 g/dL) and reduced maternal clinical infection. Vitamin D supplementation increased 25-hydroxy vitamin D levels. There was insufficient evidence for the effect on bone mineral density and serum calcium levels. Calcium supplementation did not have any significant effect on body weight, weight gain, and body mass index of the participants.ConclusionThis overview of systematic reviews reiterates the nutritional importance of vitamin A, vitamin D, and calcium supplementation for the reproductive age women. However, there was no empirical evidence available for fortification of food with vitamin A, vitamin D, and calcium and nutritional benefits of the same for reproductive age women, therefore thrusting upon the need of conducting future quality research, i.e., clinical trials and systematic reviews for food fortification.Systematic review registrationA priori protocol for this overview of systematic reviews was registered in PROSPERO with registration number CRD42018089403.

Effectiveness of a Food-Based Intervention to Increase Breast Milk Vitamin A Content at One Month of Infancy

Abstract Objectives Vitamin A requirements in early infancy are met only by breast milk intake. It is critical to ensure adequate breast milk vitamin A levels which also helps develop liver stores. The objective of the study was to evaluate the effect of a maternal food-based intervention on breast milk vitamin A content Methods Pregnant women (n = 50; 24 ± 1 week of gestation) were recruited for the randomized study. A 10 g of a green leafy vegetable powder (mint/coriander/curry) providing about 3200 μg β-carotene/day, for a period of 4 months up to 1 month of lactation were provided for intervention arm. Breast milk (BM) retinol concentration and BM volume were assessed. BM retinol and beta-carotene were assayed by HPLC and BM fat by creamatocrit method. BM retinol: fat ratio was calculated. The dose-to-mother deuterium dilution technique was used to estimate BM volume through enrichment of saliva measured by Fourier Transform Infrared Spectroscopy. Total BM retinol content was calculated from BM volume and the BM retinol (including beta-carotene:1 vitamin A RAE = 12 μg β-carotene). Inadequacy of intake was defined as proportion of infants with intake below a requirement of 400 μg RAE/day. Analysis of co-variance was performed after adjusting for age of mother, change in maternal blood retinol from baseline and BM fat, to compare outcomes between intervention and control arm. Results Maternal age, gestational age, socio-demographic characteristics and baseline vitamin A intake were comparable in both arms. Mean BM volume was similar in the 2 arms (676 ± 102 in intervention vs 630 ± 100 ml/day in control). BM retinol content (0.72 ± 0.12 vs 0.64 ± 0.11 μg/mL; P = 0.029) and BM retinol: fat ratio [0.41 (0.31, 0.47) vs 0.29 (0.21, 0.41), P = 0.011] were significantly higher in the intervention arm. The mean total BM retinol content was significantly higher in the intervention (482.2 ± 100.7 vs 406.5 ± 89.2 μg/day; P = 0.015; Cohen's effect size 0.80). Inadequacy of infant vitamin A intake was 14.3% in the intervention arm as against 39.1% in the control arm (P = 0.065). Conclusions The food-based intervention was effective in increasing vitamin A content in breast milk and thereby vitamin A intake in infants. Funding Sources International Atomic Energy Agency.

Retinol-to-Fat Ratio and Retinol Concentration in Human Milk Show Similar Time Trends and Associations with Maternal Factors at the Population Level: A Systematic Review and Meta-Analysis

Vitamin A in human milk is critical for meeting infant requirements and building liver stores needed after weaning. A number of studies have measured milk retinol, but only a subset have corrected for fat, which serves as the retinol carrier in breast milk. The purpose of the present work was to review and analyze studies in which human-milk retinol concentrations were reported in relation to milk fat and to compare these results with unadjusted breast-milk retinol concentrations in terms of time trends over the course of lactation, influences of maternal nutritional and constitutional factors, and effects of maternal vitamin A supplementation. A systematic approach was used to search the available literature by using the US National Library of Medicine's MEDLINE/PubMed bibliographic search engine. Observational and intervention studies were included if the research was original and the retinol-to-fat ratio (retinol:fat) in human milk was measured at ≥1 time point during the first 12 mo of lactation. Retinol:fat and retinol were highest in colostrum, declined rapidly in early lactation, and achieved statistical stability by 2 and 4 wk lactation, respectively. In mature milk, retinol concentration was positively correlated with milk fat (r = 0.61, P = 0.008). Breast-milk retinol:fat and retinol were positively associated with maternal vitamin A intake but were associated with plasma retinol only when dietary intake was inadequate. Postpartum supplementation with high-dose vitamin A (200,000–400,000 IU) resulted in significantly higher breast-milk retinol:fat for 3 mo and retinol for 6 mo (P < 0.05). In populations, the 2 indexes show similar trends and associations with maternal factors. Future studies should monitor how the uptake of retinol into the mammary gland affects maternal vitamin reserves, particularly in women who are at risk of vitamin A deficiency.

The effects of zinc supplementation on zinc, retinol and carotene levels in lactating Amazonian women

The effects of zinc supplementation on levels of zinc, retinol and carotene in serum and breast milk were investigated in a double blind controlled prospective study amongst 66 poor urban Amazonian mothers in 1981. The mothers predominantly breast-fed their infants for the first five months of life and took supplements from soon after birth. Milk retinol levels were already significantly higher in zinc supplemented (ZS) than non-zinc supplemented (NZS) mothers by one month post-partum, and by four months had risen significantly in the ZS mothers but fallen in NZS mothers. At four months post-partum, milk retinol levels of ZS mothers were near normal and double those of NZS mothers. The effect of zinc supplementation on these retinol levels was possibly associated with an increased absorption and utilization of dietary carotene, since milk carotene levels also increased in ZS mothers to levels three times those of NZS mothers at four months post-partum. This impact of zinc supplementation on maternal and breast milk vitamin A levels has not been shown previously and is of potential relevance where zinc and vitamin A deficiency are common.

Effect of regular consumption of provitamin A biofortified staple crops on Vitamin A status in populations in low-income countries

Biofortification of staple crops with provitamin A (PVA) carotenoids is an innovative strategy for controlling vitamin A (VA) deficiency in low-income countries (LIC). Plant breeding programs have been successful in developing biofortified varieties of cassava, maize, and orange-fleshed sweet potatoes that contain amounts of PVA-carotenoids that have the potential to impact VA status in human populations. Nutrition studies indicate that beta-carotene in biofortified staple crops is converted efficiently to VA in the body. Randomized, controlled, community-based efficacy and effectiveness trials have been conducted to assess the effect of regular consumption of PVA-carotenoid biofortified staple crops on VA status. Results indicate that regular consumption of biofortified staple crops increases plasma beta-carotene concentrations consistently, but has a moderate effect, or no effect, on VA status, when assessed by serum retinol concentration, breast milk retinol concentration, or total body VA stores. Studies are currently underway to further investigate whether consumption of biofortified staple crops improves VA status in population subgroups at risk of VA deficiency, and to better understand how to optimize the biological impact of these interventions in resource-poor settings. Keywords: Beta-carotene, Biofortification, Bioavailability, Cassava, Maize, Provitamin A, Sweet potatoes, Vitamin A

'Dose-to-Mother' Deuterium Oxide Dilution Technique: An Accurate Strategy to Measure Vitamin A Intake in Breastfed Infants.

In Mexico, infants (0–2 years old) show the highest prevalence of vitamin A deficiency (VAD), measured by serum retinol concentrations. Thus, we consider that low vitamin A (VA) intake through breast milk (BM) combined with poor weaning practices are the main factors that contribute to VAD in this group. We combined the assessment of VA status in lactating women using BM retinol and a stable isotope ‘dose-to-mother’ technique to measure BM production in women from urban and agricultural areas. Infants’ mean BM intake was 758 ± 185 mL, and no difference was observed between both areas (p = 0.067). Mean BM retinol concentration was 1.09 μmol/L, which was significantly lower for the agricultural area (p = 0.028). Based on BM retinol concentration, 57% of women were VAD; although this prevalence fell to 16% when based on fat content. Regardless of the VA biomarker used here, infants from the urban and agricultural areas cover only 66% and 49% of their dietary adequate intake from BM, respectively (p = 0.054). Our data indicate that VAD is still a public health concern in Mexico. Adopting both methods to assess VA transfer from the mother to the breastfed child offers an innovative approach towards the nutritional assessment of vulnerable groups.

Breast milk retinol concentration in mothers of preterm newborns

BackgroundPreterm newborns have low vitamin A reserves at birth, which increases their risk of morbidity and mortality. In the absence of supplementation, breast milk is the only source of this nutrient for exclusively breastfed infants. AimsTo assess retinol concentration in preterm milk and the relationship between this retinol concentration and lactation phase, degree of prematurity, and maternal serum retinol level. Study designLongitudinal study. SubjectsFifty-eight preterm mothers. Outcome measuresColostrum (1–3d), transitional (7–15d), and mature human milk (30–55d) samples were collected. Maternal blood was collected once at postpartum. Retinol level was measured using high-performance liquid chromatography. ResultsMilk retinol concentration was statistically different between lactation phases (p<0.001): 2.84±1.05μmol/L in colostrum (58), 3.47±1.28μmol/L in transitional (58), and 2.03±0.61μmol/L in mature milk (30). No difference was found in milk retinol levels between groups with different degrees of prematurity (p>0.05). Maternal serum retinol (1.82±0.50μmol/L) did not correlate with milk levels (p>0.05). ConclusionsRetinol level in preterm milk seems to be independent of the degree of prematurity and maternal serum status. A significant increase in micronutrient levels in transitional milk was observed, which is likely to contribute to reserves in the premature liver.

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.

Utilidad de un método que determina simultáneamente retinol y α-tocoferol en leche materna por cromatografía líquida de alta resolución

ObjectiveTo present the results obtained in the development of a simplified method, with a direct extraction of breast milk and detection by reverse phase high-performance liquid chromatography of retinol and α-tocopherol. Materials and methodsAn experimental 2x3 factorial design was used, with temperature variables, type of solvent and antioxidant effect, at 2 levels. Subsequent to the extraction, the samples were saponified with potassium hydroxide in methanol, then extracted with petroleum ether, and dried and reconstituted with ethanol. The chromatography conditions were established using microbondapak columns with UV/visible detector: methanol/water (96:4) mobile phase, wavelength for retinol 325, and 290nm for α-tocopherol. ResultsThe analytics parameters were: linearity; r2=0.9955 (retinol), r2=0.9808 (α-tocopherol); detection and quantification limits: 1.1μg/dL and 2.7μg/dL (retinol), 0.9μg/dL and 2.3μg/dL (α-tocopherol). Method accuracy: the within-day relative standard deviation was 4.5%, and a between-day relative standard deviation of 4.8% for retinol, and 4.9% within-day and 4.1% between-day forα-tocopherol. For accuracy, recovery=85.8±7.8% for retinol and 98±1.9% for α-tocopherol. Once validated, the method was applied to the quantification of retinol and α-tocopherol in 100 samples of breast milk. The values obtained were 63.9±5.2μg/dL for retinol and 359.0±115.0μg/dL for α-tocopherol. ConclusionThe method is selective, linear, precise, sensitive and accurate. These characteristics together with their simplicity make the validated method convenient for the determination of retinol and α-tocopherol in breast milk.

Biomarkers of Nutrition for Development (BOND)—Vitamin A Review

The Biomarkers of Nutrition for Development (BOND) project is designed to provide evidence-informed advice to anyone with an interest in the role of nutrition in health. The BOND program provides information with regard to selection, use, and interpretation of biomarkers of nutrient exposure, status, function, and effect, which will be especially useful for readers who want to assess nutrient status. To accomplish this objective, expert panels are recruited to evaluate the literature and to draft comprehensive reports on the current state of the art with regard to specific nutrient biology and available biomarkers for assessing nutritional status at the individual and population levels. Phase I of the BOND project includes the evaluation of biomarkers for 6 nutrients: iodine, folate, zinc, iron, vitamin A, and vitamin B-12. This review of vitamin A is the current article in this series. Although the vitamin was discovered >100 y ago, vitamin A status assessment is not trivial. Serum retinol concentrations are under homeostatic control due in part to vitamin A’s use in the body for growth and cellular differentiation and because of its toxic properties at high concentrations. Furthermore, serum retinol concentrations are depressed during infection and inflammation because retinol-binding protein (RBP) is a negative acute-phase reactant, which makes status assessment challenging. Thus, this review describes the clinical and functional indicators related to eye health and biochemical biomarkers of vitamin A status (i.e., serum retinol, RBP, breast-milk retinol, dose-response tests, isotope dilution methodology, and serum retinyl esters). These biomarkers are then related to liver vitamin A concentrations, which are usually considered the gold standard for vitamin A status. With regard to biomarkers, future research questions and gaps in our current understanding as well as limitations of the methods are described.