Serum Β-carotene Concentrations Research Articles

Genetic prediction of micronutrient levels and the risk of colorectal polyps: A mendelian randomization study

Previous epidemiological and experimental studies have yielded conflicting results regarding the influence of human micronutrient levels on the risk of colorectal polyps (CP). In our study, we conducted a two-sample Mendelian randomization (MR) investigation to probe the link between 13 human micronutrients (calcium, selenium, magnesium, phosphorus, folate, vitamins B-6, B-12, C, D, beta-carotene, iron, zinc, and copper) and the genetic susceptibility to CP. Summary statistics for CP (n=463,010) were obtained from pan-European genome-wide association studies, and instrumental variables for 13 micronutrients were screened from published genome-wide association studies (GWAS). After selecting suitable instrumental variables, we performed a two-sample MR study, deploying sensitivity analyses to judge heterogeneity and pleiotropy, using inverse variance weighted methods as our primary estimation tool. Our study identified that a genetic predisposition to elevated toenail and circulating selenium or serum β-carotene concentrations lowers the risk of CP occurrence. However, no statistically significant association was observed between the other 11 micronutrients and the risk of CP. The study findings provide evidence that the micronutrient selenium and β-carotene may confer protective effects against the development of CP.

Validation of resonance Raman spectroscopy-measured skin carotenoid status as a biomarker for fruit and vegetable intake in Korean adults.

Blood carotenoid concentration measurement is considered the gold standard for fruit and vegetable (F&V) intake estimation; however, this method is invasive and expensive. Recently, skin carotenoid status (SCS) measured by optical sensors has been evaluated as a promising parameter for F&V intake estimation. In this cross-sectional study, we aimed to validate the utility of resonance Raman spectroscopy (RRS)-assessed SCS as a biomarker of F&V intake in Korean adults. We used data from 108 participants aged 20-69 years who completed SCS measurements, blood collection and 3-d dietary recordings. Serum carotenoid concentrations were quantified using HPLC, and dietary carotenoid and F&V intakes were estimated via 3-d dietary records using a carotenoid database for common Korean foods. The correlations of the SCS with serum carotenoid concentrations, dietary carotenoid intake and F&V intake were examined to assess SCS validity. SCS was positively correlated with total serum carotenoid concentration (r = 0·52, 95 % CI = 0·36, 0·64, P < 0·001), serum β-carotene concentration (r = 0·60, 95 % CI = 0·47, 0·71, P < 0·001), total carotenoid intake (r = 0·20, 95 % CI = 0·01, 0·37, P = 0·04), β-carotene intake (r = 0·30, 95 % CI = 0·11, 0·46, P = 0·002) and F&V intake (r = 0·40, 95 % CI = 0·23, 0·55, P < 0·001). These results suggest that SCS can be a valid biomarker of F&V intake in Korean adults.

Associations of Serum Carotenoids With Risk of Cardiovascular Mortality Among Individuals With Type 2 Diabetes: Results From NHANES.

Although carotenoids have been suggested to exhibit antioxidant properties, some experimental studies reported that β-carotene may show pro-oxidant effects under certain conditions. Current evidence regarding the cardiovascular effects of carotenoids among patients with type 2 diabetes (T2D) is scarce. This study aimed to prospectively examine the associations of individual serum carotenoid concentrations with cardiovascular mortality among adults with T2D. This analysis included 3,107 individuals with T2D from the Third National Health and Nutrition Examination Survey (NHANES III) and NHANES 2001-2006. Cardiovascular mortality was ascertained by linkage to National Death Index records through 31 December 2015. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) and 95% CIs. During an average of 14 years of follow-up, 441 cardiovascular deaths occurred. After multivariate adjustment including lifestyles, dietary factors, glucose control, and other major carotenoids, higher serum β-carotene concentrations were significantly associated with an elevated risk of cardiovascular mortality in a dose-response manner. When extreme quartiles of β-carotene were compared, the multivariable-adjusted HR was 2.47 (95% CI 1.62, 3.76) for cardiovascular mortality (Ptrend = 0.002); and per one-unit increment in natural log-transformed serum β-carotene was associated with a 46% higher risk of cardiovascular mortality (P = 0.001). Other individual carotenoids (α-carotene, β-cryptoxanthin, lycopene, and lutein/zeaxanthin) were not significantly associated with the risk of cardiovascular mortality. Consistent results were observed when stratifying by age, sex, race, BMI, smoking status, diabetes duration, and glycated hemoglobin A1c levels. Higher concentrations of serum β-carotene, but not other individual carotenoids, were significantly associated with an increased risk of cardiovascular mortality among individuals with T2D. Our findings, if replicated, underscore the need to estimate the optimal serum β-carotene concentrations in individuals with T2D.

Serum β-carotene concentrations are associated with self-reported fatty acid intake in United States adults from the National Health and Examination Surveys.

Bioavailability of dietary β‐carotene (BC) is dependent on dose, quantity, dispersion, and presence of fat in the diet. Fats are comprised of a variety of fatty acids, which may impact the bioavailability of carotenoids. However, there is a gap in research on whether specific fatty acid classes affect serum BC concentrations in population samples. The primary objective of this study was to assess the association between reported fat and fatty acid intake and serum BC concentrations utilizing data from the National Health and Nutrition Examination Surveys (NHANES) 2003–2006. Data from 3278 NHANES participants 20–85 years old were analyzed to estimate the relationships between serum BC concentrations and reported saturated (SFA), monounsaturated (MUFA), and polyunsaturated (PUFA) fatty acid intakes. Multiple linear regression estimated ln(serum BC) based on reported fatty acid intakes adjusted for age, sex, race/ethnicity, and reported dietary BC intakes. Mean and standard error (SE) for serum BC concentrations were 14.31 ± 0.05 μg/dl. Means and SE for total fat, SFA, MUFA, and PUFA were 85.7 ± 1.3, 26.9 ± 0.4, 31.1 ± 0.5, and 17.8 ± 0.4 g, respectively. There was a significant trend for association between serum BC and reported total fat intakes (r = −0.002, p < 0.0001), but the association was not strong. Multiple linear regression showed positive associations between serum BC concentrations and higher reported dietary PUFA consumption. PUFA alpha‐linolenic acid intakes are positively associated with serum BC concentrations, while MUFA palmitoleic acid and SFA stearic acid were inversely associated with serum BC. The inverse association between MUFA and SFA suggests there may be multiple post‐digestion factors affecting serum carotenoid concentrations.

Effects of prepartum supplementation of β-carotene in Holstein cows

Whether supplemental dietary β-carotene affects periparturient cows and vitamins A and E in cows when dietary vitamin A is adequate remains uncertain. Our objective was to assess the effect of β-carotene supplementation during the close-up dry period in a herd with adequate status of vitamins A and E but low in β-carotene. The study was conducted on a large commercial dairy farm in Indiana during early summer of 2015. Ninety-four multiparous Holstein cows were assigned to either control (CON; n = 47) or β-carotene (BC; n = 47) treatments. When locked in headgates each morning, each cow received a topdress of β-carotene (Rovimix, 8 g/d; provided 800 mg of β-carotene) or carrier from 21 d before expected calving until calving. Blood samples were collected at 21 ± 1 d (mean ± standard deviation) before expected calving (before treatments began), 7 ± 1 d before calving, immediately following parturition, and 7 ± 1 d postpartum. Blood serum was analyzed for vitamins A and E, β-carotene, cholesterol, and other metabolites and enzymes. Data were analyzed using the MIXED procedure in SAS (SAS Institute Inc.). Cows had low β-carotene concentrations (0.85 μg/mL) in blood serum before treatments began. Compared with CON cows, BC cows had higher overall mean concentrations of β-carotene (2.87 μg/mL vs. 0.73 μg/mL) and retinol (165 vs. 143 ng/mL). Cows fed BC had lower α-tocopherol in serum than cows fed CON (2.26 vs. 2.46 µg/mL). Cows fed BC had lower peak milk than cows fed CON (50.9 vs. 55.3), but total lactation milk yield did not differ significantly. No effects of BC were observed on days to conception (100 d) or times bred (2.4). Treatments did not affect incidences of ketosis, retained placenta, displaced abomasum, off feed, lameness, footrot, mastitis, or metritis. In conclusion, in pregnant cows already receiving adequate vitamin A but with low serum β-carotene concentration, supplementation of β-carotene increased concentrations of β-carotene and vitamin A in blood serum, but did not affect production, reproduction, or health.

The Relationship Between Serum β-Carotene Concentrations and Reported Dietary β-Carotene Intakes Is Moderated by BMI in U.S. Adults

Abstract Objectives Serum β-carotene (BC) concentrations are not reflective of dietary BC status as serum concentrations can vary as a result of intake, lifestyle factors, adiposity, and physiological factors related to digestion and absorption. Longitudinal studies have shown a positive relationship between serum carotenoids and dietary BC intake, but the role of body mass index (BMI), as a surrogate for adiposity, in predicting serum BC concentrations is not well understood. The primary objective was to determine the role of BMI in the association between reported dietary BC intakes and serum BC concentrations. Methods Relationships between serum BC and reported dietary intake of BC were estimated using data from National Health and Nutrition Examination Surveys (NHANES)/What We Eat in America (WWEIA) survey 2003–2006 for 2580 male and non-pregnant female participants aged 20–85 years in the United States (US). The distributions of reported dietary and serum BC concentrations were skewed, therefore natural log (ln) was used to transform the data. Multivariable linear regression estimated serum BC concentrations based on reported dietary intake of BC adjusted for age, sex, race/ethnicity. Additional models were run by BMI category (normal, overweight, obesity class I, obesity class II, and obesity class III). Results Mean serum BC concentrations were 14.59 ± 0.1 μg/dL, BMI was 27.80 ± 0.1 kg/m2, and reported dietary intakes of BC were 828.82 ± 0.06 μg. A moderate association was present between serum BC and reported dietary BC intake, r = 0.30, P &amp;lt; 0.0001. When assessed according to BMI categories, the multivariable linear model shows attenuation of the β coefficient from 0.21 to 0.16, 0.12, 0.12, and 0.13 for the respective BMI categories. Conclusions In a representative sample of U.S. adults, there was a moderate association present between reported dietary BC intakes and serum BC concentrations. Additionally, the relationship between serum BC concentrations and reported dietary BC intakes was moderated by BMI, suggesting individuals with an increased BMI and/or body fat percentage may have a greater risk of low serum BC concentrations despite dietary BC intake. Funding Sources N/A.

Serum retinol, β-carotene, and α-tocopherol as biomarkers for disease risk and milk production in periparturient dairy cows

The effectiveness of using serum vitamin concentrations as biomarkers to predict diseases in dairy cows during the periparturient period is not well known. The objective of this study was to evaluate the association between serum β-carotene, retinol, and α-tocopherol concentrations and periparturient cow diseases in commercial dairies. We measured serum concentrations of these vitamin-active compounds at dry-off and during close-up (approximately 3 wk before calving) and early lactation (approximately 7 d post-calving), and we examined their association with clinical diseases in the first 30 d in milk. Diseases were diagnosed by trained personnel and recorded using database software. Blood samples were taken from 353 cows from 5 different farms over a 3-yr period. Blood samples were analyzed for β-carotene, retinol, α-tocopherol, and cholesterol. We built separate mixed logistic regression models for each disease outcome: hyperketonuria, lameness, mastitis, uterine diseases (retained placenta or metritis), and an aggregate outcome. For the aggregate outcome, a cow was considered positive if she had one or more of the following: hyperketonuria, lameness, mastitis, uterine disease, pneumonia, milk fever, or displaced abomasum. Concentrations of all 3 fat-soluble vitamins decreased significantly in early lactation relative to the 2 prepartum sampling times. Serum retinol concentrations at close-up and early lactation were negatively associated with odds of developing postpartum hyperketonuria. At early lactation, cows with uterine disease had lower serum retinol concentrations than cows without uterine disease. Similarly, lower serum retinol concentrations were associated with greater odds of having any one disease in the aggregate outcome. First-test 305-d mature-equivalent milk yield was positively correlated with increased serum α-tocopherol and negatively correlated with β-carotene concentrations. This study demonstrates the potential for serum β-carotene, retinol, and α-tocopherol to serve as biomarkers for disease risk.

Effects of 2,4-thiazolidinedione (TZD) on milk fatty acid profile and serum vitamins in dairy goats challenged with intramammary infusion of Streptococcus uberis.

The study included two experiments. In the first, 24 lactating Saanen dairy goats received low-energy diet without vitamin supplements. Twelve goats received a daily IV injection of 2,4- thiazolidinedione (TZD), others received saline injection. A week later, 6 goats from each treatment were challenged with intramammary infusion (IMI) of saline (CTRL) or Streptococcus uberis. In the second experiment, 12 Saanen lactating dairy goats received supplemental vitamins to reach NRC recommendation level. Six goats in each group were injected with TZD or saline daily, and 14 d later received Streptococcus uberis IMI in the right half of the udder. The hypotheses were (1) TZD does not affect the level of retinol in blood, and (2) the fatty acid profile is affected by the interaction between mammary infection and TZD in dairy goats. In the first experiment blood samples were collected on d -7, -2, 1, 2, 12 and milk samples were collected on d -8, 1, 4, 7, and 12, both relative to IMI. In the second experiment, blood samples were collected on d -15, 0, 1, and 10 relative to IMI. Milk and serum samples were analyzed for retinol, α-tocopherol and fatty acid profile. Serum retinol and β-carotene concentrations were higher in the second experiment compared to the first. Serum β-carotene and α-tocopherol were greater in TZD than CTRL and there was a TZD × time interaction in the first experiment. In addition, the TZD × time interaction showed that the milk fatty acid were reduced in C16 : 0 while C18 : 3 n3 while total omega 3 fatty acids were increased, as well as with minor effect on preventing a transient increase in α-tocopherol in milk. Overall, the TZD may affect the lipid-soluble vitamins and fatty acid profile, potentially altering immune responses, during mastitis in dairy goats.

Exopolysaccharides from milk fermented by lactic acid bacteria enhance dietary carotenoid bioavailability in humans in a randomized crossover trial and in rats

Dietary supplementation with carotenoids can have beneficial health effects, but carotenoids are poorly absorbed. We aimed to evaluate how milk fermented by lactic acid bacteria affects dietary carotenoid bioavailability in humans and rats and to investigate mechanisms by which active components in milk fermented by Lactobacilli enhance dietary carotenoid absorption. Male rats (n=8/group) were administered β-carotene or β-carotene+fermented milk. Rats (n=6/group) were also pretreated with ezetimibe, a cholesterol absorption inhibitor, to investigate β-carotene transport mechanisms. In humans, 3 studies were conducted using a randomized crossover method. Subjects (n=16/study) consumed a vegetable (carrot, tomato, or spinach) drink alone or with a fermented milk drink. Blood samples were collected at various time points after consumption. In rats, the serum β-carotene area under the concentration-time curve (AUC) was significantly higher for the β-carotene+fermented milk than for β-carotene only. A significant correlation (r=0.83, P<0.001) between the exopolysaccharide (EPS) content of fermented milk and serum β-carotene AUC was observed. Ezetimibe treatment did not suppress elevations in serum β-carotene concentrations induced by fermented milk ingestion. In humans, the incremental area under the concentration-time curve (iAUC) for β-carotene in the plasma triacylglycerol-rich lipoprotein (TRL) fraction was significantly (1.8-fold, range: 0.6-3.9) higher when carrot+fermented milk was consumed compared with carrot drink alone. A significantly (6.5-fold, range: 0.04-7.7) higher iAUC for lycopene in the plasma TRL fraction was observed for subjects who consumed tomato+fermented milk compared with tomato drink alone. A significant increase in plasma lutein in all fractions was observed after consumption of spinach+fermented milk, but not with spinach drink alone. Co-ingestion of β-carotene and fermented milk significantly increased dietary β-carotene bioavailability in humans and rats. EPSs could affect the physical properties of fermented milk to enhance dietary β-carotene absorption mediated by simple diffusion mechanisms. These findings may be relevant for methods to increase dietary carotenoid bioavailability.This trial was registered at umin.ac.jp/ctr as UMIN000034838, UMIN000034839, and UMIN000034840.

Time-course Changes in the Relationship between Serum and Milk β-carotene Concentrations in Mid-lactation Dairy Cows following a Shift from Drylot Feeding to Time-limited Grazing

Time-course Changes in the Relationship between Serum and Milk β-carotene Concentrations in Mid-lactation Dairy Cows following a Shift from Drylot Feeding to Time-limited Grazing

Preconception serum lipids and lipophilic micronutrient levels are associated with live birth rates after IVF.

Is a mixture of preconception serum lipids and lipophilic micronutrients associated with clinical pregnancy and live births? In this prospective cohort study, blood serum was collected on the day of oocyte retrieval for 180 women undergoing IVF at an academic reproductive health centre. Concentrations of lipids (phospholipids, total cholesterol, high- and low-density lipoproteins, and triglycerides) and lipophilic micronutrients (α-, δ-, and γ-tocopherols, retinol, β- and α-carotenes, β-cryptoxanthin, lutein and lycopene) were determined using diagnostic reagent kits and high-performance liquid chromatography. Poisson regression was used with robust variance estimation to evaluate changes in Z-scores for the mixture of serum lipid and lipophilic micronutrient concentrations as predictors of embryo implantation, clinical pregnancy and live birth, adjusted for age, body mass index (BMI), race, smoking status, infertility diagnosis, ovarian stimulation protocol and other measured lipid and lipophilic micronutrient concentrations. Each SD higher serum triglyceride concentration was associated with a lower chance of live birth (RR 0.54; 95% CI 0.33 to 0.90) whereas a 1 SD higher serum α-tocopherol concentration, as part of a mixture of serum lipids and lipophilic micronutrients, was associated with a higher likelihood for a live birth (RR 1.61; 95% CI 1.11 to 2.36). Serum β-carotene concentrations were associated with live birth in a non-linear fashion; low β-carotene was associated with a lower chance of live birth and high β-carotene with a higher chance of live birth. Although components of a mixture of lipids and lipophilic micronutrients were associated with live birth outcomes after IVF, a larger investigation is necessary to fully evaluate the potential clinical implications.

Vitamin A status in healthy women eating traditionally prepared spirulina (Dihé) in the Chad Lake area.

BackgroundChad Lake is a central place in a region with a high prevalence of vitamin A deficiency. Spirulina, a natural source of β-carotene, is traditionally produced and eaten as “Dihé” around Chad Lake. β-carotene spirulina has been found to have a high conversion factor to retinol. The aim of the study was to assess if the retinol status between healthy women eating spirulina Dihé daily (SPI+) and not (SPI-) in the Chad Lake area was different.MethodsThis study was observational: 88 healthy women were recruited and selected according to clinical criteria and their willingness to participate. They were divided in two groups according to their Dihé daily consumption: those who eat Dihé (SPI+; n = 35) and those who do not (SPI-; n = 35). After anthropometric and dietary assessments, blood retinol, β-carotene, retinol binding, and inflammatory/nutritional proteins were measured.ResultsThe diet between groups was identical, except for β-carotene consumption, which was higher in SPI+ than in SPI- (10.8 vs. 1.8 mg/day). The serum retinol and β-carotene concentrations were significantly higher in SPI+ than in SPI- at 1.26 ± 0.36 μmol/l versus 1.03 ± 0.31 μmol/l (p = 0.008) and 0.59 ±0.37 μmol/l versus 0.46± 0.31 μmol/l (p = 0.04), respectively. Seventy-seven percent of SPI+ versus 29% of SPI- had an adequate blood retinol value (p = 0.01).ConclusionThe results confirm that β-carotene in spirulina is an effective positive modulator of blood retinol status. Dihé is a potential natural source of β-carotene to achieve a proper vitamin A status in healthy women living near Chad Lake.

Impact of biofortified maize consumption on serum carotenoid concentrations in Zambian children.

Biofortified maize, designed as an intervention strategy to prevent vitamin A deficiency, can provide upwards of 15 μg β-carotene per g dry weight. Some varieties also have elevated concentrations of other carotenoids. We conducted a cluster randomized, controlled feeding trial in rural Zambia to test the impact of daily consumption of biofortified maize over a 6-month period on vitamin A status. Serum concentrations of retinol and carotenoids were assessed by high-performance liquid chromatography. Data on circulating carotenoids by intervention group in 679 children are reported here. As previously shown, consumption of this β-carotene-rich maize significantly improved serum β-carotene concentrations (0.273 vs. 0.147 μmol/L, p < 0.001, in this subset of children). Here we show significant increases in α-carotene, β-cryptoxanthin, and zeaxanthin (p < 0.001). There was no impact on lutein or lycopene concentrations. Consumption of biofortified maize can have broader implications beyond the control of vitamin A deficiency (Trial registration: NCT01695148).

Provitamin A-biofortified maize consumption increases serum xanthophylls and 13C-natural abundance of retinol in Zambian children.

Plants that undergo C4 photosynthesis, such as maize, are enriched in the stable isotope of carbon (13C) compared with other dietary plants and foods. Consumption of maize that has been biofortified to contain elevated levels of provitamin A carotenoids (orange maize) increased the abundance of 13C in serum retinol of Mongolian gerbils. We evaluated this method in humans to determine if it has potential for further use in intervention effectiveness studies. A random subset of samples from a two-month randomized controlled feeding trial of rural three- to five-year old Zambian children were used to determine the impact of orange maize intake on serum carotenoid concentrations ( n = 88) and 13C-natural abundance in serum retinol ( n = 77). Concentrations of β-cryptoxanthin (a xanthophyll provitamin A carotenoid) and the dihydroxy xanthophylls lutein and zeaxanthin, which do not have vitamin A activity, were elevated in children consuming orange maize compared with those consuming a white maize control ( P < 0.001), while β-carotene was not different ( P > 0.3). Furthermore, 13C natural abundance was higher after two months' intervention in the orange maize group compared with the white maize group ( P = 0.049). Predictions made from equations developed in the aforementioned gerbil study estimated that maize provided 11% (2-21%, 95% confidence interval) of the recent dietary vitamin A to these children. These results demonstrate that orange maize is efficacious at providing retinol to the vitamin A pool in children through provitamin A carotenoids, as monitored by the change in 13C enrichment, which was not reflected in serum β-carotene concentrations. Further effectiveness studies in countries who have adopted orange maize should consider determining differences in retinol 13C-enrichment among target groups in addition to profiling serum xanthophyll carotenoids with specific emphasis on zeaxanthin. Impact statement Maize biofortified with provitamin A carotenoids (orange) has been released in some African markets. Responsive and sensitive methods to evaluate dissemination effectiveness are needed. This study investigated methods to evaluate effectiveness of orange maize consumption using serum from Zambian children fed orange maize for two months. Many varieties of orange maize contain higher amounts of the xanthophyll carotenoids in addition to β-carotene compared with typical varieties. This study uniquely showed higher concentrations of the maize xanthophylls lutein, zeaxanthin, and β-cryptoxanthin in children who consumed orange maize compared with white. Furthermore, maize is a C4 plant and is therefore naturally enriched with 13C. Higher 13C was detected in the serum retinol of the orange maize consumers with no change in serum β-carotene concentration suggesting preferential bioconversion to retinol. The combined analyses of serum zeaxanthin specifically and 13C-natural abundance of retinol could prove useful in effectiveness studies between orange maize adopters and non-adopters.

Common SNP rs6564851 in the BCO1 Gene Affects the Circulating Levels of β-Carotene and the Daily Intake of Carotenoids in Healthy Japanese Women.

The circulating levels of β-carotene are modulated not only by sex, but also by autosomal gene variations and fruit intake. The aim of this study was to investigate the interactions between β-carotene metabolism-related gene single nucleotide polymorphisms (SNPs; genetic factors) and nutrient intake (environmental factors) relating to their effects on circulating β-carotene. The serum concentrations of β-carotene and the habitual food intake of 92 healthy Japanese adults were examined. All subjects were genotyped for three common SNPs: rs6564851 in the β-carotene 15,15′-oxygenase 1 (BCO1) gene, rs2278986 in the scavenger receptor class B member 1 (SCARB1) gene and rs362090 in the intestine-specific homeobox (ISX) gene. Univariate analysis revealed that the circulating β-carotene levels were significantly higher in rs6564851 GG homozygotes (p = 0.003). Additionally, the daily intake of β-cryptoxanthin was positively associated with the circulating β-carotene levels in female GG homozygotes of rs6564851 (p = 0.023), and the daily intake of α- and β-carotenes, and β-cryptoxanthin was significantly lower in female rs6564851 T allele carries than in female GG homozygotes (p = 0.009, 0.008, 0.009, respectively). The present study apparently indicates that higher circulating β-carotene levels in female rs6564851 GG homozygotes depend on carotenoid intake.

Maternal serum retinol and β-carotene concentrations and neonatal bone mineralization: results from the Southampton Women’s Survey cohort

Background: Studies in older adults and animals have suggested contrasting relations between bone health and different vitamin A compounds. To our knowledge, the associations between maternal vitamin A status and offspring bone development have not previously been elucidated.Objective: We examined the associations between maternal serum retinol and β-carotene concentrations during late pregnancy and offspring bone mineralization assessed at birth with the use of dual-energy X-ray absorptiometry.Design: In the Southampton Women’s Survey mother-offspring birth cohort, maternal health, lifestyle, and diet were assessed prepregnancy and at 11 and 34 wk of gestation. In late pregnancy, maternal serum retinol and β-carotene concentrations were measured. Offspring total body bone mineral density (BMD), bone mineral content (BMC), and bone area (BA) were measured within 2 wk after birth.Results: In total, 520 and 446 mother-offspring pairs had measurements of maternal serum retinol and β-carotene, respectively. Higher maternal serum retinol in late pregnancy was associated with lower offspring total body BMC (β = −0.10 SD/SD; 95% CI: −0.19, −0.02; P = 0.020) and BA (β = −0.12 SD/SD; 95% CI: −0.20, −0.03; P = 0.009) but not BMD. Conversely, higher maternal serum β-carotene concentrations in late pregnancy were associated with greater total body BMC (β = 0.12 SD/SD; 95% CI: 0.02, 0.21; P = 0.016) and BA (β = 0.12 SD/SD; 95% CI: 0.03, 0.22; P = 0.010) but not BMD.Conclusions: Maternal serum retinol and β-carotene concentrations had differing associations with offspring bone size and growth at birth: retinol was negatively associated with these measurements, whereas β-carotene was positively associated. These findings highlight the need for further investigation of the effects of maternal retinol and carotenoid status on offspring bone development.

Provitamin A–biofortified maize increases serum β-carotene, but not retinol, in marginally nourished children: a cluster-randomized trial in rural Zambia

Background: Vitamin A deficiency remains a nutritional concern in sub-Saharan Africa. Conventionally bred maize hybrids with high provitamin A carotenoid concentrations may have the potential to improve vitamin A status in maize-consuming populations.Objective: We evaluated the efficacy of regular provitamin A carotenoid–biofortified “orange” maizemeal (∼15 μg β-carotene/g) consumption in improving vitamin A status and reducing vitamin A deficiency in children.Design: This was a cluster-randomized controlled trial in the rural farming district of Mkushi, Zambia. All 4- to 8-y-old children in an ∼400-km2 area were identified and grouped by proximity into clusters of ∼15–25 children. We randomly assigned clusters to 1) orange maizemeal (n = 25), 2) white maizemeal (n = 25), or 3) a parallel, nonintervention group (n = 14). Children in intervention clusters (n = 1024) received 200 g maizemeal for 6 d/wk over 6 mo; the maizemeal was prepared according to standardized recipes and served in cluster-level kitchens. Staff recorded attendance and leftovers. We collected venous blood before and after the intervention to measure serum retinol, β-carotene, C-reactive protein, and α1-acid glycoprotein.Results: Intervention groups were comparable at baseline, and vitamin A status was better than anticipated (12.1% deficient on the basis of serum retinol <0.7 μmol/L). Although attendance at meals did not differ (85%), median daily maize intake was higher in white (154 g/d) than in orange (142 g/d) maizemeal clusters. At follow-up, mean serum β-carotene was 0.14 μmol/L (95% CI: 0.09, 0.20 μmol/L) higher in orange maizemeal clusters (P < 0.001), but mean serum retinol (1.00 ± 0.33 μmol/L overall) and deficiency prevalence (17.1% overall) did not differ between arms.Conclusion: In this marginally nourished population, regular biofortified maizemeal consumption increased serum β-carotene concentrations but did not improve serum retinol. This trial was registered at clinicaltrials.gov as NCT01695148.

Biofortified yellow cassava and vitamin A status of Kenyan children: a randomized controlled trial

Whereas conventional white cassava roots are devoid of provitamin A, biofortified yellow varieties are naturally rich in β-carotene, the primary provitamin A carotenoid. We assessed the effect of consuming yellow cassava on serum retinol concentration in Kenyan schoolchildren with marginal vitamin A status. We randomly allocated 342 children aged 5-13 y to receive daily, 6 d/wk, for 18.5 wk 1) white cassava and placebo supplement (control group), 2) provitamin A-rich cassava (mean content: 1460 μg β-carotene/d) and placebo supplement (yellow cassava group), and 3) white cassava and β-carotene supplement (1053 μg/d; β-carotene supplement group). The primary outcome was serum retinol concentration; prespecified secondary outcomes were hemoglobin concentration and serum concentrations of β-carotene, retinol-binding protein, and prealbumin. Groups were compared by using ANCOVA, adjusting for inflammation, baseline serum concentrations of retinol and β-carotene, and stratified design. The baseline prevalence of serum retinol concentration <0.7 μmol/L and inflammation was 27% and 24%, respectively. For children in the control, yellow cassava, and β-carotene supplement groups, the mean daily intake of cassava was 378, 371, and 378 g, respectively, and the total daily supply of provitamin A and vitamin A from diet and supplements was equivalent to 22, 220, and 175 μg retinol, respectively. Both yellow cassava and β-carotene supplementation increased serum retinol concentration by 0.04 μmol/L (95% CI: 0.00, 0.07 μmol/L); correspondingly, serum β-carotene concentration increased by 524% (448%, 608%) and 166% (134%, 202%). We found no effect on hemoglobin concentration or serum concentrations of retinol-binding protein and prealbumin. In our study population, consumption of yellow cassava led to modest gains in serum retinol concentration and a large increase in β-carotene concentration. It can be an efficacious, new approach to improve vitamin A status. This study was registered with clinicaltrials.gov as NCT01614483.

Long-term trends in the metabolic profile test results in German Holstein dairy herds in Thuringia, Germany

Systematic metabolic profile tests at regular intervals provide important information to meet the increasing challenges in managing dairy herds. This study aimed at deriving long-term trends from the results of metabolic profile tests in Thuringian German Holstein dairy herds. Blood and urine samples were collected from 710 fresh, high yielding, and dry cows, respectively, to monitor 13 parameters including the serum non-esterified fatty acids (NEFA), β-hydroxybutyrate (BHB), bilirubin, β-carotene and urea concentrations, the serum of aspartate aminotransferase and glutamate dehydrogenase activities, the serum concentrations of the minerals calcium, inorganic phosphate and selenium, the urine potassium and sodium concentrations, and the net acid-base excretion (NABE). A total of 17,070 group samples from 103 herds were collected during 1997-2014. Period prevalence of aberrant groups was calculated for each parameter and year accordingly. Using a linear regression model, a long-term trend of the period prevalence was determined. To account for the 15 aberrancies possible for each stage of lactation, seven significant trends were found for dry, nine for fresh, and ten for lactating cows. A decrease of the period prevalence was detected for increased NEFA, for low serum β-carotene, selenium, inorganic phosphate, and urea concentrations, for low sodium and high potassium urine concentrations, and for increased NABE. In contrast, period prevalence increased significantly for cases with increased serum aspartate aminotransferase and glutamate dehydrogenase activities, increased bilirubin concentration, and low NABE. Metabolic profile tests enable a description of the herd health status using objectively measured data as a basis for the implementation of measures to optimize herd management to improve the herd health status.

Associations of serum β-carotene and retinol concentrations with insulin resistance: The Toon Health Study

ObjectiveAlthough green and yellow vegetables have beneficial effects against type 2 diabetes, the relationship of their nutritive content with insulin resistance is poorly understood. The aim of this study was to examine the associations of serum β-carotene and retinol concentrations with glucose and insulin concentrations. MethodsWe recruited 951 Japanese men and women ages 30 to 79 y who were not undergoing treatment for diabetes and measured their serum β-carotene and retinol concentrations. A 75-g oral glucose tolerance test was performed and the homeostasis model assessment for insulin resistance (HOMA-IR) and the Matsuda Index were calculated as measures of insulin resistance. Several confounding factors were adjusted for with multivariable logistic models. ResultsMultivariable-adjusted odds ratios of the highest quartile of serum β-carotene compared with the lowest quartile for HOMA-IR >1.6 and Matsuda Index <4.9 were 0.56 (95% confidence interval, 0.34–0.94) and 0.62 (0.37–1.02), respectively. When stratified by sex and overweight status, these associations were observed for women and non-overweight individuals. Serum retinol concentration was not associated with either index. Furthermore, according to the nutritional survey, serum β-carotene concentration was associated with green and yellow vegetable intake (P = 0.01). ConclusionOur findings suggest that higher serum β-carotene levels, associated with higher intake of green and yellow vegetables, confer beneficial effects against insulin resistance.