Serum Retinol Concentrations Research Articles

Vitamin D Maintains Growth and Bone Mineral Density against a Background of Severe Vitamin A Deficiency and Moderate Toxicity in a Swine Model.

Excessive vitamin A (VA) negatively impacts bone. Interactions between VA and vitamin D (VD) in bone health are not well-understood. This study used a traditional two-by-two factorial design. Pigs were weaned and randomized to four treatments (n = 13/group): -A-D, -A+D, +A-D, and +A+D for 3 and 5 wk. Serum, liver, kidney, adrenal glands, spleen, and lung were analyzed by ultra-performance LC. Growth was evaluated by weight measured weekly and BMD by DXA. Weights were higher in -A+D (18.1 ± 1.0 kg) and +A+D (18.2 ± 2.3 kg) at 5 wk than in -A-D (15.5 ± 2.1 kg) and +A-D (15.8 ± 1.5 kg). Serum retinol concentrations were 0.25 ± 0.023, 0.22 ± 0.10, 0.77 ± 0.12, and 0.84 ± 0.28 µmol/L; and liver VA concentrations were 0.016 ± 0.015, 0.0065 ± 0.0035, 2.97 ± 0.43, 3.05 ± 0.68 µmol/g in -A-D, -A+D, +A-D, and +A+D, respectively. Serum 25(OH)D3 concentrations were 1.5 ± 1.11, 1.8 ± 0.43, 27.7 ± 8.91, and 23.9 ± 6.67 ng/mL in -A-D, +A-D, -A+D, +A+D, respectively, indicating a deficiency in -D and adequacy in +D. BMD was highest in +D (p < 0.001). VA and the interaction had no effect on BMD. Dietary VD influenced weight gain, BMD, and health despite VA status.

Calculation of reference intervals for the concentrations of α-tocopherol and retinol in serum using indirect data-mining procedures

BackgroundEstablishing adequate reference intervals (RIs) for vitamins A and E is essential for diagnosing and preventing deficiencies. Due to the current boom in data mining and its easy applicability, more laboratories are establishing RIs using indirect methods. Our study aims to obtain RIs using four indirect data-mining procedures (Bhattacharya, Hoffmann, Kosmic, and RefineR) for vitamins A and E. Material and methods8943 individuals were collected to establish the RIs. After using different data cleaning steps and checking whether these data should be divided according to age and gender based on multiple linear regression and variance component analyses, indirect RIs were calculated using specific Excel spreadsheets or R-packages software. ResultsA total of 2004 records were eligible. For vitamin A, the RIs obtained were (1.11 − 2.68) µmol/L, (1.13 − 2.70) µmol/L, (1.13 − 2.71) µmol/L, and (1.17 − 2.66) µmol/L using the Bhattacharya, Hoffmann, Kosmic and RefineR approaches, respectively. For vitamin E, these intervals were (17.3 − 49.9) µmol/L (Bhattacharya), (17.3 − 48.9) µmol/L (Hoffmann), (19.6 − 50.3) µmol/L (Kosmic), and (19.4 − 50.9) µmol/L (RefineR). In all cases, the RIs were comparable. ConclusionsSuitable RIs for vitamins A and E were calculated using four indirect methods that are suitable and adapted to our population’s demographic characteristics.

Early postnatal high-dose fat-soluble enteral vitamin A supplementation for moderate or severe bronchopulmonary dysplasia or death in extremely low birthweight infants (NeoVitaA): a multicentre, randomised, parallel-group, double-blind, placebo-controlled, investigator-initiated phase 3 trial

Vitamin A plays a key role in lung development, but there is no consensus regarding the optimal vitamin A dose and administration route in extremely low birthweight (ELBW) infants. We aimed to assess whether early postnatal additional high-dose fat-soluble enteral vitamin A supplementation versus placebo would lower the rate of moderate or severe bronchopulmonary dysplasia or death in ELBW infants receiving recommended basic enteral vitamin A supplementation. This prospective, multicentre, randomised, parallel-group, double-blind, placebo-controlled, investigator-initiated phase 3 trial conducted at 29 neonatal intensive care units in Austria and Germany assessed early high-dose enteral vitamin A supplementation (5000 international units [IU]/kg per day) or placebo (peanut oil) for 28 days in ELBW infants. Eligible infants had a birthweight of more than 400 g and less than 1000 g; gestational age at birth of 32+0 weeks postmenstrual age or younger; and the need for mechanical ventilation, non-invasive respiratory support, or supplemental oxygen within the first 72 h of postnatal age after admission to the neonatal intensive care unit. Participants were randomly assigned by block randomisation with variable block sizes (two and four). All participants received basic vitamin A supplementation (1000 IU/kg per day). The composite primary endpoint was moderate or severe bronchopulmonary dysplasia or death at 36 weeks postmenstrual age, analysed in the intention-to-treat population. This trial was registered with EudraCT, 2013-001998-24. Between March 2, 2015, and Feb 27, 2022, 3066 infants were screened for eligibility at the participating centres. 915 infants were included and randomly assigned to the high-dose vitamin A group (n=449) or the control group (n=466). Mean gestational age was 26·5 weeks (SD 2·0) and mean birthweight was 765 g (162). Moderate or severe bronchopulmonary dysplasia or death occurred in 171 (38%) of 449 infants in the high-dose vitamin A group versus 178 (38%) of 466 infants in the control group (adjusted odds ratio 0·99, 95% CI 0·73-1·55). The number of participants with at least one adverse event was similar between groups (256 [57%] of 449 in the high-dose vitamin A group and 281 [60%] of 466 in the control group). Serum retinol concentrations at baseline, at the end of intervention, and at 36 weeks postmenstrual age were similar in the two groups. Early postnatal high-dose fat-soluble enteral vitamin A supplementation in ELBW infants was safe, but did not change the rate of moderate or severe bronchopulmonary dysplasia or death and did not substantially increase serum retinol concentrations. Deutsche Forschungsgemeinschaft and European Clinical Research Infrastructures Network (ECRIN).

Lower serum carotenoid levels are associated with incident cognitive decline independent of traditional risk factors in a prospective study of older men from Northern Ireland

AbstractBackgroundNutritional influences, and antioxidant status in particular, have been implicated in the aetiology of cognitive decline. This study investigated the neuroprotective effects of serum antioxidants in a prospective cohort of older men to identify associations with cognitive outcomes, independent of traditional risk factors.MethodThis cohort study included 873 Northern Irish men nested within PRIME (Prospective Epidemiological Study of Myocardial Infarction) who were followed‐up for at least 15 years. Mini Mental State Examination (MMSE) was carried out at baseline. The Addenbrooke’s Cognitive Examination‐R and MMSE were carried out at follow‐up. A consensus diagnosis of normal cognition for age, mild cognitive impairment (MCI) or dementia was made using accepted clinical criteria. Serum concentrations of retinol, two forms of vitamin E (α‐ and ϒ‐tocopherol) and six carotenoids measured from baseline samples were quantified by high‐performance liquid chromatography and assessed by multiple logistic regression analyses.ResultThe case definition included the 163 men characterised with MCI and 46 men with dementia; 664 participants were considered cognitively normal controls (Table 1). In unadjusted analyses, serum levels of the carotenoids α‐carotene, β‐carotene, lycopene and β‐cryptoxanthin were significantly lower in MCI/dementia cases than controls, in contrast to ϒ‐tocopherol, which was significantly higher (Table 2). Following adjustment for traditional risk factors including height, APOε4 genotype, diastolic blood pressure, smoking status and the presence of (pre)diabetes or depression, the effect size of those carotenoids significant in the unadjusted analysis was attenuated somewhat; only α‐carotene remained significantly associated with MCI/dementia (odds ratio = 0.55; confidence interval: 0.31‐0.99; Table 2).ConclusionOur data implicates lower levels of serum carotenoids as potential early biomarkers of MCI/ dementia before overt manifestation of symptoms, independent of traditional risk factors. These findings are consistent with hypotheses supportive of a neuroprotective role of dietary antioxidants and corroborate previous associations of higher serum carotenoid levels with better cognition in aging subjects. There is emerging evidence that carotenoids, through their potent antioxidant and anti‐inflammatory properties, may positively impact cognitive function. Limiting cognitive decline through lifestyle, exercise, and a higher carotenoid intake, may prove beneficial.

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.

Heat Stress Impairs Male Reproductive System with Potential Disruption of Retinol Metabolism and Microbial Balance in the Testis of Mice

BackgroundHeat stress (HS) has a harmful impact on the male reproductive system, primarily by reducing the sperm quality. The testicular microenvironment plays an important role in sperm quality. ObjectivesThis study aimed to explore the underlying mechanism by which HS impairs the male reproductive system through the testicular microenvironment. MethodsTen-week-old male mice (n = 8 mice/group) were maintained at a normal temperature (25°C, control) or subjected to HS (38°C for 2 h each day, HS) for 2 wk. The epididymides and testes were collected at week 2 to determine sperm quality, histopathology, retinol concentration, the expression of retinol metabolism-related genes, and the testicular microbiome. The testicular microbiome profiles were analyzed using biostatistics and bioinformatics; other data were analyzed using a 2-sided Student’s t test. ResultsCompared with the control, HS reduced (P < 0.05) sperm count (42.4%) and motility (97.7%) and disrupted the integrity of the blood–testis barrier. Testicular microbial profiling analysis revealed that HS increased the abundance of the genera Asticcacaulis, Enhydrobacter, and Stenotrophomonas (P < 0.05) and decreased the abundance of the genera Enterococcus and Pleomorphomonas (P < 0.05). Notably, the abundance of Asticcacaulis spp. showed a significant negative correlation with sperm count (P < 0.001) and sperm motility (P < 0.001). Moreover, Asticcacaulis spp. correlated significantly with most blood differential metabolites, particularly retinol (P < 0.05). Compared with the control, HS increased serum retinol concentrations (25.3%) but decreased the testis retinol concentration by 23.7%. Meanwhile, HS downregulated (P < 0.05) the expression of 2 genes (STRA6 and RDH10) and a protein (RDH10) involved in retinol metabolism by 27.3%–36.6% in the testis compared with the control. ConclusionsHS reduced sperm quality, mainly because of an imbalance in the testicular microenvironment potentially caused by an increase in Asticcacaulis spp. and disturbed retinol metabolism. These findings may offer new strategies for improving male reproductive capacity under HS.

Impact of modifiable lifestyle risk factors for prostate cancer prevention: a review of the literature.

Although prostate cancer (PCa) is one of the most common cancers among men, the impact of modifiable risk and protective factors is still being debated. This review aims to qualitatively summarize the most recent studies related to potential healthy lifestyle factors affecting the development of PCa. The literature focusing on modifiable risk factors for prostate cancer was reviewed. Medline and Embase via the Ovid database were searched, and all relevant and inherent articles were analyzed. Non-eligible publications, such as review articles, editorials, comments, guidelines, or case reports, were excluded. This review confirms that there is strong evidence that being overweight or obese increases the risk of advanced prostate cancer (assessed by body mass index (BMI), waist circumference, and waist-hip ratio), particularly considering central adiposity and ethnicity as contributing factors. The possible contribution of smoking still seems not entirely clear, while alcohol seems to affect PCa prevention in patients taking 5α-reductase inhibitors (5-ARIs). Dietary fibers may have anti-inflammatory properties and improve insulin sensitivity by reducing IGF bioactivity. In particular, dietary fiber intake like insoluble and legume fibers may be inversely associated with prostate cancer risk. Also, hyperglycemia and hyperinsulinemia, with untreated diabetic fasting blood glucose levels, could be modifiable prostate cancer risk factors. In two studies, aspirin was associated with a lower risk of lethal PCa and overall mortality. Concerning the role of vitamins, despite conflicting and divergent results, serum retinol concentration seems to be associated with an increased risk of prostate cancer and high-grade prostate cancer. Some studies resulted in disagreement about the role of selenium and vitamin E. We found inconsistent and controversial findings about the association between vitamin D and prostate cancer risk. Far from being conclusive evidence, our findings confirm some strong evidence already found in the previous literature and highlight the need to clarify the role of some risk factors whose role is not yet completely known. This effort would facilitate the cultural and social change that may allow the shift from the treatment of prostate cancer when diagnosed to the real efforts needed for systematic prevention.

Serum concentrations of retinol, β-carotene and zinc in women with breast cancer submitted to radiotherapy according to prior treatment modality and toxicity

Serum concentrations of retinol, β-carotene and zinc in women with breast cancer submitted to radiotherapy according to prior treatment modality and toxicity

Dietary intake of preformed vitamin A and provitamin A carotenoids are not associated with serum retinol and carotenoid concentrations among children 36-59months of age in rural Burkina Faso: a cross-sectional study.

This study aimed to assess the association between dietary intake of preformed vitamin A (VA) and pro-VA carotenoids and serum retinol and carotenoid concentrations among 36-59-month-old children in a rural area in Burkina Faso. Two community-based cross-sectional studies were conducted in a rural area of Burkina Faso and included 115 children aged 36-59months. Dietary intake of preformed VA and pro-VA was assessed directly by 24-h dietary recall. Serum retinol and carotenoid (α- and β-carotene, and β-cryptoxanthin) concentrations were measured. The associations between serum retinol and carotenoid concentrations and their respective dietary intake were assessed by multiple linear regression. Geometric mean [95% CI] adjusted serum retinol concentration in children was 0.86 [0.81; 0.92] µmol/L. The prevalence of low adjusted serum retinol concentration (< 0.7µmol/L) was 26.8%. Geometric mean [95% CI] serum carotenoid concentrations were: α-carotene (0.03 [0.02; 0.03] µmol/L), β-carotene (0.14 [0.12; 0.16] µmol/L), and β-cryptoxanthin (0.17 [0.15; 0.21] µmol/L). Dietary intakes of α- and β-carotene and adjusted serum retinol and α-carotene concentrations were significantly higher during the rainy season. In multiple linear regressions, no associations were found between dietary intakes of preformed VA and pro-VA carotenoids and serum retinol and carotenoid concentrations in children aged 36-59months in Burkina Faso. There was no effect of season on the associations between preformed VA and pro-VA carotenoids intake and serum retinol and carotenoid concentrations. This study shows that dietary intakes of preformed VA and pro-VA carotenoids based on 24-h dietary recall method cannot be used as proxy of serum retinol and carotenoid concentrations in this population. The study was registered retrospectively (22 March 2018) as a clinical trial with the Pan African Clinical Trials Registry (Cochrane South Africa; PACTR201803002999356).

Autism Spectrum Disorder is Related to Increasing Intestinal Prevotella That Can Be Regulated by Vitamin A

Background: Increasing studies suggest that the microbiome-gut-brain axis plays a fundamental role in developing autism spectrum disorder (ASD). Objectives: We aimed to explore biomarkers from gut bacteria in ASD and the dietary vitamin A (VitA) relationship with intestinal bacteria of autistic children and provide a theoretical basis for dietary regulation of ASD. Methods: Ten autistic children aged 2 to 6 from special training facilities were enrolled from 2017 to 2018. At the same time, 10 healthy children aged 2 to 6 from a kindergarten were collected as a control. All participants were from Chongqing, China. The 16sRNA amplicon sequencing was used to analyze children's intestinal bacteria. The serum retinol level was detected by high-performance liquid chromatography (HPLC), and children's dietary intake was analyzed using three-day 24-hour dietary recalls. Results: There were significant differences in alpha diversity between the groups. Also, a higher relative abundance of Prevotellaceae, Prevotella 9, and Roseburia was observed among ASD children. We also found decreases in 9 bacteria (Enterobacteriales, Gammaproteobacteria, Enterobacteriaceae, Clostridiaceae 1, Clostridium sensu stricto 1, Escherichia-Shigella, Bacteroides fragilis, Escherichia coli, and Clostridium neonatale). Dietary VitA intake and serum retinol concentration were lower in the ASD group than in the control group. Meanwhile, serum VitA had a significantly negative correlation with the abundance of intestinal Prevotella 9. Conclusions: Our study helps identify some bacterial biomarkers for ASD, as in previous reports. Meanwhile, the study suggests that dietary VitA may be involved in the clinical symptoms of ASD by regulating the intestinal bacteria Prevotella. It may provide a new way to treat ASD in the future. Further studies are needed to identify the results by expanding the sample size and developing animal experiments.

Inadequate Niacin Intake Disrupts Growth and Retinol Homeostasis Resulting in Higher Liver and Lower Serum Retinol Concentrations in Male Rats

BackgroundNiacin-derived nicotinamide adenine dinucleotide is an essential cofactor for many dehydrogenase enzymes involved in vitamin A (VA) metabolism. Several countries with high prevalence of VA deficiency rely on maize, a poor source of available niacin, as a dietary staple. ObjectivesThis study evaluated the interaction of dietary niacin on VA homeostasis using male Sprague-Dawley rats, aged 21 d (baseline body weight 88.3 ± 6.6 g). MethodsAfter 1 wk of acclimation, baseline samples were collected (n = 4). Remaining rats (n = 54) were split into 9 groups to receive low tryptophan, VA-deficient feed with 3 different amounts of niacin (0, 15, or 30 mg/kg) and 3 different oral VA doses (50, 350, or 3500 nmol/d) in a 3 × 3 design. After 4 wk, the study was terminated. Serum, livers, and small intestine were analyzed for retinoids using high-performance liquid chromatography. Niacin and metabolites were evaluated with nuclear magnetic resonance. Plasma pyridoxal-P (PLP) was measured with high-performance liquid chromatography. ResultsNiacin intake correlated with serum retinol concentrations (r = 0.853, P < 0.001). For rats receiving the highest VA dose, liver retinol concentrations were lower in the 30-mg/kg niacin group (5.39 ± 0.27 μmol/g) than those in the 0-mg/kg and 15-mg/kg groups (9.18 ± 0.62 and 8.75 ± 0.07 μmol/g, respectively; P ≤ 0.05 for both). This phenomenon also occurred in the lower VA doses (P ≤ 0.05 for all). Growth and tissue weight at endline were associated with niacin intake (P ≤ 0.001 for all). Plasma PLP correlated with estimated niacin intake (r = 0.814, P < 0.001). ConclusionsOptimal niacin intake is associated with lower liver VA and higher serum retinol and plasma PLP concentrations. The extent to which vitamin B intake affects VA homeostasis requires further investigation to determine if the effects are maintained in humans.

ASSOCIATION OF SERUM RETINOL CONCENTRATION WITH CARDIOVASCULAR DISEASES IN THE US NATIONAL HEALTH AND NUTRITION EXAMINATION SURVEY (NHANES) 2001-2006

Objective: The association between serum retinol concentration and cardiovascular disease is controversial. This study aimed to investigate the relationship between serum retinol concentration and cardiovascular diseases. Design and method: This cross-sectional study included 8240 non-pregnant participants aged over 20 in the National Health and Nutrition Examination Survey (NHANES) 2001-2006. Cardiovascular diseases were defined as a self-reported history of coronary heart diseases, heart attacks, angina pectoris, and stroke. Restricted cubic spline and logistic regression were employed to examine the association of serum retinol concentration with cardiovascular diseases with adjustments for potential confounders (i.e., demographics, socioeconomic status, body mass index, physical activity, alcohol, smoking, medical history, and use of vitamin A supplements). Results: 6.8% (95% CI, 6.0-7.6) of the participants had cardiovascular diseases. The mean (±standard error) serum retinol concentration was 2.06±0.13 μmol/L. Serum retinol concentration had a J-shaped relationship with cardiovascular diseases, with the lowest risk observed between 0.82 and 1.20 μmol/L. Stratified by gender, the serum retinol concentration with the lowest odds ratio was 0.99 μmol/L in men and 1.07 μmol/L in women. The lower and upper tail of serum retinol concentrations (&lt; 0.82μmol/L or &gt;1.20μmol/L) were associated with cardiovascular diseases [OR = 1.70, 95%CI (1.23-1.85), P&lt;0.01] after adjusting for covariates. Conclusions: Serum retinol concentration has a J-shaped association with cardiovascular diseases. While serum retinol may be an independent predictor of cardiovascular diseases, further studies are needed to determine if this is a causal relationship.

Seasonal Vitamin A Depletion in Grazing Horses Is Assessed Better by the Relative Dose Response Test than by Serum Retinol Concentration

Vitamin A influences growth and reproduction in horses. A retinol dose response (RDR) test for retinol has been shown to be better than serum retinol concentration for assessing vitamin A status in other species, so we have compared these two methods in the horse. Forty-five Thoroughbred broodmares were assigned randomly to three groups fed pasture and hay (PH), pasture, hay and vitamin A-free concentrate (PHC), or hay and concentrate (HC) in early summer (May 1991). Mares in pasture groups produced 23 foals (March through June) that had access to their dam's diets and were also studied. In the mares, significant vitamin A depletion developed in 2 mo in the nonpasture group (HC) and in 8 mo in the two pasture groups (PH and PHC) according to the RDR test, and in all three groups at 8 mo as shown by a decrease in serum retinol concentration. In the weanlings (PH and PHC only), no differences between groups were found for serum retinol, but the RDR was significantly higher in the PH group, which had suffered a respiratory infection, than in the PHC group. These findings indicated that vitamin A depletion was detected more readily by the RDR test than by serum retinol concentration, that consumption of pasture delayed depletion in the late fall, and that infection was associated with lower vitamin A status.

Assessment of Skin Carotenoid Measurement as a Means to Detect Vitamin A Deficiency in Children and Pregnant Women of Nepal

BackgroundVitamin A deficiency (VAD) is an ongoing public health concern among children and pregnant women in Nepal despite robust national efforts to screen and treat this vision- and life-threatening condition. ObjectivesThis study aimed to evaluate skin carotenoid scores measured using the Veggie Meter as a rapid, noninvasive screening tool for VAD in Nepali children and pregnant women. MethodsThis comparative cross-sectional study enrolled 164 pregnant women and 168 children (aged 8 to 12 y) from public hospitals in three distinct outlying ecological regions of Nepal (Terai, Hill, and Mountain). The primary outcome assessed whether skin carotenoid status could be a biomarker for VAD. We determined skin carotenoid scores using the Veggie Meter and compared them with serum retinol and total carotenoid concentrations assessed by HPLC. Correlation analysis was used to determine bivariate associations between serum retinol and total carotenoid concentrations, and the Veggie Meter assessed skin carotenoid status. Receiver operating characteristics curves were determined, and a P value <0.05 was considered statistically significant. ResultsWe found that 8.5% of pregnant women and 13.0% of children in this study had severe VAD (serum retinol < 200 ng/mL). There were significant correlations between skin carotenoid scores with serum retinol and total carotenoid concentrations among pregnant women and children (r = 0.253–0.530, P ≤ 0.001). The Veggie Meter detected severe VAD with 57.1% sensitivity and 82.7% specificity in pregnant women and 61.9% sensitivity and 75.9% specificity in children. ConclusionsAlthough sensitivity and specificity were moderate for detecting VAD with the Veggie Meter, skin carotenoid assessment using this rapid, noninvasive portable device could still be valuable for high-risk VAD screening in Nepal and similar developing countries with limited access to laboratory measurement of serum vitamin A concentrations.

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.

Retinoic acid associates with mortality of patients on long-term hemodialysis

Background Retinol concentrations in serum are significantly higher in patients on hemodialysis (HD) compared to healthy controls. Its lower concentrations have been reported to be an independent predictor of mortality. ATRA – all-trans retinoic acid – is an important compound related to retinol. The objective was to determine ATRA concentrations in serum and to find their association with the prognosis of patients on long-term HD. Methods ATRA was determined by high-performance liquid chromatography in a group of 247 HD patients (follow-up five years) and 54 healthy controls. Results Although serum retinol concentrations were higher in the studied cohort of HD patients, ATRA was lower – median 1.13 (interquartile range 0.90–1.60) ng/mL in HD patients versus 1.42 (1.08–1.63) ng/mL in healthy controls, p = 0.02. Lower ATRA was significantly related to overall mortality of HD patients (HR (95%CI) 0.63 (0.47–0.85) per interquartile range, p = 0.003). The best prognosis was observed in patients with concentrations of both ATRA and retinol above the median (p = 0.003). Conclusions We detected decreased retinoic acid levels in HD patients compared to healthy controls. Lower concentrations of ATRA represent a significant predictor of mortality and provide additional information to retinol.

Effect Modification of Selenium Supplementation by Intake and Serum Concentrations of Antioxidants on the Development of Metachronous Colorectal Adenoma

BackgroundSelenium (Se) is a trace element that has been investigated as a potential chemopreventive agent for colorectal cancer. Dietary intake of other antioxidant nutrients may modify the effect of Se.ObjectiveWe examined the association between intake and serum concentrations of retinol, β-carotene, β-cryptoxanthin, lycopene, lutein/zeaxanthin, and α- and γ-tocopherol and the development of metachronous colorectal adenoma, and if these nutrients modified the effect of Se.MethodsWe conducted a prospective study of 1874 participants from the Se Trial with data for antioxidant intake, as well as a subcohort of 508 participants with serum biomarker concentrations.ResultsStatistically significantly lower odds for the development of metachronous adenoma were observed for those participants in the highest tertile of intake for lutein/zeaxanthin compared to the lowest, with an OR (95% CI) of 0.72 (0.56-0.94). No effect modification for intake of any nutrient was observed. However, circulating concentrations of lycopene exhibited statistically significant effect modification of selenium supplementation (p < 0.06),ConclusionThese findings show that intake and circulating concentrations of antioxidant nutrients were not consistently associated with reduced odds for the development of metachronous lesions, although blood concentrations of lycopene may modify the effect of selenium supplementation.

Visceral and body adiposity are negatively associated with vitamin A nutritional status independently of Body Mass Index and recommended intake of vitamin A in Brazilian Women

Vitamin A (VA) has a negative association with body mass index (BMI) since it is involved in the regulation of body adiposity via nuclear receptors. However, few studies have investigated the relationship between VA nutritional status and the way body adipose is stored, which is the aim of this cross-sectional analytical study with Brazilian adult women in different BMI classes with the intake of VA recommended. VA nutritional status was assessed by serum retinol and β-carotene measurements, dietary intake, and diagnosis of night blindness (NB). Results: 268 women with mean age of 38.00±5.80 years. According to the BMI, 30.97% were normal weight, 14.18% overweight, 25.37% class I obesity, 14.55% class II, and 14.93% class III.The prevalence of low serum of β-carotene, retinol, and presence of NB in the total sample was 73.5%, 45.9%, and 20.1%, respectively. A total of 86.7% of normal weight women had inadequate visceral adiposity index (VAI) and 41.0% had inadequate body adiposity index (BAI).VAI was the body adiposity marker with the highest association with low serum retinol and b-carotene concentrations (P<.001). There was presence of NB in 100% of cases of inadequacy of BAI (P<.001). High visceral and body adiposity were associated with compromised VA nutritional status regardless of BMI and the recommended intake of VA. Additional measures to assess body adiposity, and especially its distribution, may collaborate in clinical practice to identify women at risk of compromising their VA nutritional status even when they are classified as normal weight according to their BMI.

Enteral Low-Dose Vitamin A Supplementation in Preterm or Low Birth Weight Infants to Prevent Morbidity and Mortality: a Systematic Review and Meta-analysis.

To assess effects of enteral "low" dose (daily doses of ≤10 000 international unit) vitamin A supplementation compared with no vitamin A supplementation in human milk-fed preterm and low birth weight (LBW) infants. Cochrane Central Register of Controlled Trials; Medline, Embase, Scopus, Web of Science, CINAHL from inception to 16 March 2021. Randomized trials were screened. Primary outcomes were mortality, morbidity, growth, neurodevelopment. Secondary outcomes were feed intolerance and duration of hospitalization. We also assessed the dose and timing of vitamin A supplementation. Data were extracted and pooled with fixed and random-effects models. Four trials including 800 very LBW <1.5 kg or <32 weeks' gestation infants were found. At latest follow-up, we found little or no effect on: mortality, sepsis, bronchopulmonary dysplasia, retinopathy of prematurity, duration of hospitalisation. However, we found a increased level of serum retinol mean difference of 4.7 μg/ml (95% CI 1.2 to 8.2, I2 =0.00%, one trial, 36 participants,). Evidence ranged from very low to moderate certainty. There were no outcomes reported for length, head circumference or neurodevelopment. Heterogeneity and small sample size in the included studies. Low-dose vitamin A increased serum retinol concentration among very LBW and very preterm infants but had no effect on other outcomes. More trials are needed to assess effects on clinical outcomes and to assess effects in infants 1.5 to 2.4 kg or 32 to 26 weeks' gestation.

Health outcomes associated with micronutrient-fortified complementary foods in infants and young children aged 6–23 months: a systematic review and meta-analysis

SummaryBackgroundAppropriate feeding of infants and young children is essential for healthy growth and the prevention of stunting, wasting, and overweight. We aimed to assess the beneficial versus harmful effects of providing fortified complementary foods to children in the complementary feeding period.MethodsIn this systematic review and meta-analysis, we searched the databases Cochrane Central Register of Controlled Trials, MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature, Global Index Medicus, Web of Science, ClinicalTrials.gov, and WHO International Clinical Trials Registry Platform from inception to March 9, 2021. We included randomised controlled trials and controlled clinical trials done in infants and children aged 6–23 months with no identified health problems. Consumption of foods fortified centrally (ie, during industrial processing) with one micronutrient or a combination of vitamins, minerals, or both was compared with the same complementary foods, but without micronutrient fortification. Two review authors independently screened studies for eligibility, extracted data, assessed risk of bias, and rated the certainty of the evidence. The main outcomes were growth (measured by Z scores for weight for age, weight for height or length, and height or length for age, or other growth measures), stunting, wasting, nutrient adequacy or excess, anaemia, haemoglobin concentration, iron status, serum zinc concentration, and serum retinol concentration. We used a random-effects meta-analysis for combining data. This study is registered with PROSPERO, CRD42021245876.FindingsWe included 16 studies with 6423 participants, 13 of which were done in malaria-endemic areas. Overall, 12 studies were included in the quantitative syntheses. We identified five further ongoing studies. There was no difference between participants who received fortified complementary foods and those who received non-fortified complementary foods in weight-for-age Z scores (mean difference −0·01, 95% CI −0·07 to 0·06; five trials; 1206 participants; moderate-certainty evidence), weight-for-height or length Z scores (−0·05, −0·19 to 0·10; four trials; 1109 participants; moderate-certainty evidence), and height or length-for-age Z scores (−0·01, −0·21 to 0·20; four trials; 811 participants; low-certainty evidence); stunting and wasting were not assessed in any study as outcomes. Moderate-certainty evidence from six trials with 1209 patients showed that providing fortified complementary foods to children aged 6–23 months reduced the risk of anaemia (risk ratio 0·57, 95% CI 0·39 to 0·82). Those who received fortified complementary foods compared with those who did not had higher haemoglobin concentrations (mean difference 3·44 g/L, 95% CI 1·33 to 5·55; 11 trials; 2175 participants; moderate-certainty evidence) and ferritin concentration (0·43 μg/L on log scale, 0·14 to 0·72; six trials; 903 participants; low-certainty evidence). The intervention led to no effects on serum zinc concentration (−0·13 g/dL, −0·82 to 0·56; two trials; 333 participants; low-certainty evidence) and serum retinol concentration (0·03 μmol/L, −0·02 to 0·08; five trials; 475 participants; moderate-certainty evidence).InterpretationFortified complementary foods are effective strategies to prevent anaemia in infants and young children aged 6–23 months in malaria-endemic regions. Effects of complementary food fortification should be further investigated in low-income and middle-income countries, but should also be assessed in high-income countries, and in regions where malaria is not endemic.FundingWHO.