Low ß-carotene bioaccessibility and bioavailability from high fat, dairy-based meal.

PURPOSE: The original aim of the study was to determine, in a double-blind 3-arm crossover human trial (n = 7), the effect of supplemental levels of iron (25 mg) and zinc (30 mg) on ß-carotene (synthetic) bioavailability (10 h postprandial). However, despite the high dose of supplemental ß-carotene (15 mg) consumed with the high fat (18 g), dairy-based breakfast test meal, there was a negligible postprandial response in plasma and triglyceride rich fraction ß-carotene concentrations. We then systematically investigated the possible reasons for this low bioavailability of ß-carotene. METHODS: We determined (1) if the supplemental ß-carotene could be micellised and absorbed by epithelial cells, using a Caco-2 cell model, (2) if the fat from the test meal was sufficiently bioavailable to facilitate ß-carotene bioavailability, (3) the extent to which the ß-carotene could have been metabolised and converted to retinoic acid/retinol and (4) the effect of the test meal matrix on the ß-carotene bioaccessibility (in vitro digestion) and Caco-2 cellular uptake. RESULTS: We found that (1) The supplemental ß-carotene could be micellised and absorbed by epithelial cells, (2) the postprandial plasma triacylglycerol response was substantial (approximately 75-100 mg dL-1 over 10 h), indicating sufficient lipid bioavailability to ensure ß-carotene absorption, (3) the high fat content of the meal (approximately 18 g) could have resulted in increased ß-carotene metabolism, (4) ß-carotene bioaccessibility from the dairy-based test meal was sixfold lower (p < 0.05) than when digested with olive oil. CONCLUSION: The low ß-carotene bioavailability is probably due to a combination of the metabolism of ß-carotene to retinol by BCMO1 and interactions of ß-carotene with the food matrix, decreasing the bioaccessibility. TRAIL REGISTRATION: The human trail was retrospectively registered (ClinicalTrail.gov ID: NCT05840848).

Associations of serum carotenoids with all-cause and cardiovascular mortality in adults with MAFLD.

BACKGROUND AND AIMS: The associations between serum carotenoids and mortality are contradictory in various metabolic-associated diseases. This study aimed to examine the associations of five major serum carotenoids with mortality among adults with metabolic dysfunction-associated fatty liver disease (MAFLD). METHODS AND RESULTS: This analysis included 3040 individuals with MAFLD from the Third National Health and Nutrition Examination Survey (NHANES III). All-cause and cardiovascular mortality were ascertained by linkage to the National Death Index through December 31, 2019. Cox proportional hazards regression models were employed to estimate hazard ratios (HRs) and 95% confidence intervals (CIs), and restricted cubic spline (RCS) analyses were performed to assess the linearity of the associations. During a follow-up period of 826,547 person-years, 1325 all-cause and 429 cardiovascular deaths occurred. For all-cause mortality, compared with those in the lowest quartiles, the multivariable-adjusted HRs (95% CIs) in the highest quartiles were 0.63 (0.49-0.81) for α-carotene; 0.65 (0.52-0.80) for ß-carotene; 0.64 (0.51-0.81) for ß-cryptoxanthin; 0.73 (0.56-0.95) for lycopene; and 0.69 (0.52-0.91) for lutein/zeaxanthin. For cardiovascular mortality, the multivariable-adjusted HRs (95% CIs) in the highest quartiles were 0.51 (0.33-0.78) for α-carotene; 0.54 (0.35-0.82) for ß-carotene; 0.52 (0.34-0.80) for ß-cryptoxanthin; 0.63 (0.44-0.90) for lycopene; and 0.62 (0.39-0.99) for lutein/zeaxanthin. Besides, serum α-carotene, ß-cryptoxanthin, and lycopene exhibited linear correlations with all-cause mortality in MAFLD adults, and four serum carotenoids, except ß-carotene, were linearly correlated with cardiovascular mortality. CONCLUSIONS: Lower serum α-carotene, ß-carotene, ß-cryptoxanthin, lycopene, and lutein/zeaxanthin concentrations were associated with higher risk of all-cause and cardiovascular mortality in US adults with MAFLD.

Genetically predicted circulating concentrations of micronutrients and risk of hypertensive disorders of pregnancy: a Mendelian randomization study.

PURPOSE: Epidemiological studies examining the association between circulating micronutrients and the risk of hypertensive disorders during pregnancy (HDP) have produced inconsistent results. Therefore, we conducted a Mendelian randomization (MR) analysis to evaluate the potential causal relationship between micronutrients and HDP. METHODS: Nine micronutrients (beta-carotene, vitamin B6, vitamin B12, calcium, zinc, selenium, copper, folate, and phosphorus) were selected as the exposure factors. Summary data for gestational hypertension (14,727 cases and 196,143 controls) and preeclampsia/eclampsia (7212 cases and 174,266 controls) were extracted from the FinnGen consortium. The MR analysis employed the inverse variance weighted method and conducted a range of sensitivity analyses. RESULTS: The inverse variance weighted method indicated no significant causal relationship between nine genetically predicted micronutrient concentrations and gestational hypertension, as well as preeclampsia/eclampsia. Sensitivity analyses suggested the absence of pleiotropy. CONCLUSION: There is no strong evidence to support the causation between circulating micronutrients and hypertensive disorder during pregnancy.

Serum retinol, ß-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 ß-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 ß-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 ß-carotene concentrations. This study demonstrates the potential for serum ß-carotene, retinol, and α-tocopherol to serve as biomarkers for disease risk.

Biomarker-based validity of a food frequency questionnaire estimating intake in Brazilian children and adolescents.

This study evaluated the validity of nutrient and food group intakes estimated by an FFQ against biomarkers. A 71-item semiquantitative FFQ was administered to 210 Brazilian children and adolescents aged 9-13 years. Intakes were correlated with biomarkers in plasma and red blood cells. Correlations between nutrients and their biomarkers were presented for animal protein, myristic acid (C14:0), EPA, DHA, ß-carotene, folate, and vitamins B3, B5 and B6. Food groups and biomarkers were correlated as follows: fish products with EPA and DHA; milk and dairy with C14:0, pyridoxal 5'-phosphate and vitamin B12; total vegetables and dark green and orange vegetables with ß-carotene; 5-methyltetrahydrofolate with green vegetables; and flour products with para-aminobenzoylglutamic acid. This FFQ is a valid tool for ranking Brazilian children and adolescents according to their intake of several nutrients and food groups.

Serum Retinol and Risk of Overall and Site-Specific Cancer in the ATBC Study.

Retinol, the most biologically active form of vitamin A, might influence cancer-related biological pathways. However, results from observational studies of serum retinol and cancer risk have been mixed. We prospectively examined serum retinol and risk of overall and site-specific cancer in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study (n = 29,104 men), conducted in 1985-1993, with follow-up through 2012. Serum retinol concentration was measured using reverse-phase high-performance liquid chromatography. Cox proportional hazards models estimated the association between baseline serum retinol quintile and overall and site-specific cancer risk in 10,789 cases. After multivariable adjustment, higher serum retinol was not associated with overall cancer risk (highest vs. lowest quintile: hazard ratio (HR) = 0.97, 95% confidence interval (CI): 0.91, 1.03; P for trend = 0.43). Higher retinol concentrations were, however, associated with increased risk of prostate cancer (highest vs. lowest quintile: HR = 1.28, 95% CI: 1.13, 1.45; P for trend < 0.0001) and lower risk of both liver and lung cancers (highest vs. lowest quintile: for liver, HR = 0.62, 95% CI: 0.42, 0.91; P for trend = 0.004; and for lung, HR = 0.80, 95% CI: 0.72, 0.88; P for trend < 0.0001). No associations with other cancers were observed. Understanding the mechanisms that underlie these associations might provide insight into the role of vitamin A in cancer etiology.

Serum Beta Carotene and Overall and Cause-Specific Mortality.

RATIONALE: Although the health effects of beta carotene have been studied extensively, a systematic examination of serum concentrations and long-term mortality, including cardiovascular disease mortality, has not been reported. OBJECTIVE: Explore whether serum beta carotene is associated with overall and cause-specific mortality and to elucidate the strength and dose-response of the association. METHODS AND RESULTS: We conducted a prospective serological analysis of 29 103 men in the ATBC study (Alpha-Tocopherol, Beta-Carotene Cancer Prevention). During 31 years of follow-up, 23 796 deaths occurred, including deaths because of cardiovascular disease (9869), cancer (7692), respiratory disease (2161), diabetes mellitus (119), injuries and accidents (1255), and other causes (2700). Serum beta carotene was assayed using high-performance liquid chromatography. Adjusting for major risk factors measured, men with higher serum beta carotene had significantly lower all-cause mortality (hazard ratios=0.81, 0.71, 0.69, and 0.64 for quintile 2 (Q2)-Q5 versus Q1, respectively; Ptrend<0.0001). Serum beta carotene was significantly associated with risk of death from cardiovascular disease, heart disease, stroke, cancer, respiratory disease, diabetes mellitus, injuries and accidents, and other causes (Q5 versus Q1, hazard ratio=0.21-0.73, all Ptrend<0.0001). The all-cause mortality association was not materially impacted by adjustment for fruit and vegetable consumption (albeit, estimated with some measurement error) and was generally similar across subgroups of smoking intensity, alcohol consumption, trial supplementation, and duration of follow-up, but was significantly modified by age, years of smoking, and body mass index, with stronger inverse associations among men who were younger, smoked fewer years, and had a lower body mass index (all Pinteraction≤0.0025). CONCLUSIONS: This study provides evidence that higher beta carotene biochemical status is associated with lower overall, cardiovascular disease, heart disease, stroke, cancer, and other causes of mortality. The dose-response associations over a 30-year period were not attenuated by adjustment for other important risk factors and support greater fruit and vegetable consumption as a means to increase beta carotene status and promote longevity.

Associations between serum carotenoid levels and the risk of non-Hodgkin lymphoma: a case-control study.

Limited studies have investigated the effects of serum carotenoids on the risk of non-Hodgkin lymphoma (NHL), and the findings have been inconclusive. This study aims to assess the association between serum total or specific carotenoid levels and NHL risk. This 1:1 matched, hospital-based case-control study enrolled 512 newly diagnosed (within 1 month) NHL patients and 512 healthy controls who were matched by age (±5 years) and sex in Urumqi, China. Serum carotenoid levels were measured by HPLC. Conditional logistic regression showed that higher serum total carotenoid levels and their subtypes (e.g. α-carotene, ß-carotene, ß-cryptoxanthin and lycopene) were dose-dependently associated with decreased NHL risk. The multivariable-adjusted OR and their 95 % CI for NHL risk for quartile 4 (v. quartile 1) were 0·31 (95 % CI 0·22, 0·48; Pfor trend < 0·001) for total carotenoids, 0·52 (95 % CI 0·33, 0·79; Pfor trend: 0·003) for α-carotene, 0·63 (95 % CI 0·42, 0·94; Pfor trend: 0·031) for ß-carotene, 0·73 (95 % CI 0·49, 1·05; Pfor trend: 0·034) for ß-cryptoxanthin and 0·51 (95 % CI 0·34, 0·75; Pfor trend: 0·001) for lycopene. A null association was observed between serum lutein + zeaxanthin and NHL risk (OR 0·89, 95 % CI 0·57, 1·38; Pfor trend: 0·556). Significant interactions were observed after stratifying according to smoking status, and inverse associations were more evident among current smokers than past or never smokers for total carotenoids, α-carotene and lycopene (Pfor heterogeneity: 0·047, 0·042 and 0·046). This study indicates that higher serum carotenoid levels might be inversely associated with NHL risk, especially among current smokers.

Beta-carotene, telomerase activity and Alzheimer's disease in old age subjects.

PURPOSE: Advancing age represents the strongest risk factor for Alzheimer's disease (AD), and the identification of biomarkers able to define what characterizes physiological aging from AD may represent a potential starting point for novel preventive strategies. Among these biomarkers, telomeres seem to be a promising target. Interestingly, high intake of carotenoid-rich food may play a role in protecting telomeres by oxidative stress reduction. Accordingly, low plasma ß-carotene concentrations have been found in AD subjects when compared with cognitively healthy subjects. In this study, we aim at investigating the hypothesis that low ß-carotene might be associated with markers of accelerated cellular aging, including leucocyte telomere length (LTL) and peripheral mononuclear cell (PBMC) telomerase activity in a cohort of old age subjects. METHODS: The study was conducted in 68 old age subjects, 37 AD, and 31 age-matched healthy controls. In all subjects, ß-carotene plasma level, LTL and peripheral telomerase activity were measured. RESULTS: In all populations, ß-carotene significantly and positively (r = 0.320, p = 0.008) correlated with telomerase activity, independent of gender. A model having telomerase activity levels as the dependent variable, and age, gender, smoking habit, and ß-carotene as independent variables, confirmed that ß-carotene was independently associated with telomerase activity (ß = 0.319, p = 0.012). Subjects affected by AD had significantly lower plasmatic levels of ß-carotene (448 ± 66 mg/ml vs 497 ± 59 mg/ml, p = 0.001) and LTL (0.53 ± 0.25 vs 0.69 ± 0.29; p = 0.009) as compared with healthy controls. Β-carotene plasma level was associated with AD diagnosis (OR 0.988; IC95% 0.978-0.997; p = 0.013) independently of age, gender, smoking habit, ApoE genotype, and LTL. CONCLUSION: Our data show that ß-carotene may modulate telomerase activity in old age. Moreover, lower plasma ß-carotene levels, correlating with peripheral telomerase activity, are associated with AD diagnosis independent of multiple covariates.

Effect of dispersed form on the bioavailability of ß-carotene from daily intake in humans.

In a randomized double-blind crossover study, a canned beverage was prepared using an emulsion dispersion formulation (EM) of ß-carotene and a crystal dispersion formulation (CR) of ß-carotene; the beverages were ingested by human subjects daily for 2 weeks to compare the ß-carotene bioavailability. EM-ß-carotene enhanced the ß-carotene concentrations in human plasma approximately 4-fold, but CR-ß-carotene showed no statistically significant enhancement. Bioaccessibility is the ratio of the solubilized fraction to the whole amount ingested. Bioaccessibility of ß-carotene from EM-ß-carotene was higher than that from CR-ß-carotene in an in vitro digestion test. Contrarily, ß-carotene from CR-ß-carotene, consists of all-trans-ß-carotene, was higher than that from EM-ß-carotene, consists of a mixture of cis and all-trans-ß-carotene, on the uptake by intestinal Caco-2 cells, suggesting that bioaccessibility was a critical factor in ß-carotene bioavailability in this study. EM-ß-carotene thus has potential as a food coloring agent with value added because it enhances ß-carotene bioavailability.

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 ß-carotene concentrations were higher in the second experiment compared to the first. Serum ß-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.

Prospective serum metabolomic profiling of lethal prostate cancer.

Impaired metabolism may play an important role in the pathogenesis of lethal prostate cancer, yet there is a paucity of evidence regarding the association. We conducted a large prospective serum metabolomic analysis of lethal prostate cancer in 523 cases and 523 matched controls nested within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study. Median time from baseline fasting serum collection to prostate cancer death was 18 years (maximum 30 years). We identified 860 known biochemicals through an ultrahigh-performance LC-MS/MS platform. Conditional logistic regression models estimated odds ratios (OR) and 95% confidence intervals of risk associated with 1-standard deviation (s.d.) increases in log-metabolite signals. We identified 34 metabolites associated with lethal prostate cancer with a false discovery rate (FDR) < 0.15. Notably, higher serum thioproline, and thioproline combined with two other cysteine-related amino acids and redox metabolites, cystine and cysteine, were associated with reduced risk (1-s.d. OR = 0.75 and 0.71, respectively; p ≤ 8.2 × 10-5 ). By contrast, the dipeptide leucylglycine (OR = 1.36, p = 8.2 × 10-5 ), and three gamma-glutamyl amino acids (OR = 1.28-1.30, p ≤ 4.6 × 10-4 ) were associated with increased risk of lethal prostate cancer. Cases with metastatic disease at diagnosis (n = 179) showed elevated risk for several lipids, including especially the ketone body 3-hydroxybutyrate (BHBA), acyl carnitines, and dicarboxylic fatty acids (1.37 ≤ OR ≤ 1.49, FDR < 0.15). These findings provide a prospective metabolomic profile of lethal prostate cancer characterized by altered biochemicals in the redox, dipeptide, pyrimidine, and gamma-glutamyl amino acid pathways, whereas ketone bodies and fatty acids were associated specifically with metastatic disease.

Single Nucleotide Polymorphisms in ß-Carotene Oxygenase 1 are Associated with Plasma Lycopene Responses to a Tomato-Soy Juice Intervention in Men with Prostate Cancer.

BACKGROUND: Human plasma and tissue lycopene concentrations are heterogeneous even when consuming controlled amounts of tomato or lycopene. OBJECTIVES: Our objective is to determine whether single nucleotide polymorphisms (SNPs) in or near known or putative carotenoid metabolism genes [ß-carotene 15,15' monooxygenase 1 (BCO1), scavenger receptor class B type 1 (SCARB1), ATP-binding cassette transporter subfamily A member 1 (ABCA1), microsomal triglyceride transfer protein (MTTP), apolipoprotein B-48, elongation of very long chain fatty acids protein 2 (ELOVL2), and ATP-binding cassette subfamily B member 1 (ABCB1), and an intergenic superoxide dismutase 2, mitochondrial-associated SNP] are predictive of plasma lycopene responses to steady state tomato juice consumption. METHODS: Secondary linear regression analyses of data from a dose-escalation study of prostate cancer patients [n = 47; mean ± SEM age: 60 ± 1 y; BMI (in kg/m2): 32 ± 1] consuming 0, 1, or 2 cans of tomato-soy juice/d (163 mL/can; 20.6 mg lycopene 1.2 mg ß-carotene/can) for 24 ± 0.7 d before prostatectomy were conducted to explore 11 SNP genotype effects on the change in plasma lycopene and plasma and prostate tissue concentrations of lycopene, ß-carotene, phytoene, and phytofluene. RESULTS: Two BCO1 SNP genotypes were significant predictors of the change in plasma lycopene, with SNP effects differing in magnitude and direction, depending on the level of juice intake (rs12934922 × diet group P = 0.02; rs6564851 × diet group P = 0.046). Further analyses suggested that plasma ß-carotene changes were predicted by BCO1 rs12934922 (P < 0.01), prostate lycopene by trending interaction and main effects of BCO1 SNPs (rs12934922 × diet group P = 0.09; rs12934922 P = 0.02; rs6564851 P = 0.053), and prostate ß-carotene by BCO1 SNP interaction and main effects (rs12934922 × diet group P = 0.01; rs12934922 P < 0.01; rs7501331 P = 0.02). CONCLUSIONS: In conclusion, SNPs in BCO1 and other genes may modulate human plasma and prostate tissue responses to dietary lycopene intake and warrant validation in larger, human controlled feeding intervention and cohort studies. Genetic variants related to carotenoid metabolism may partially explain heterogeneous human blood and tissue responses and may be critical covariates for population studies and clinical trials. This trial was registered at clinicaltrials.gov as NCT01009736.

Serum and Erythrocyte Biomarkers of Nutrient Status Correlate with Short-Term Α-Carotene, Β-Carotene, Folate, and Vegetable Intakes Estimated by Food Frequency Questionnaire in Military Recruits.

OBJECTIVE: Food frequency questionnaires (FFQs) estimate habitual dietary intake and require evaluation in populations of interest in order to determine accuracy. Thus, the purpose of this study was to determine agreement between circulating biomarkers and FFQ estimated dietary intake in a military population consuming all meals in a dining facility over 12 weeks. METHODS: 2014 Block FFQs were administered and fasted blood samples were drawn to assess nutritional biomarkers at the end of a 12-week training period in male (n = 141) and female (n = 125) Marine recruits undergoing initial military training. FFQ estimates of alpha- and beta-carotene, folate, and fruit and vegetable intake and circulating concentrations of serum alpha- and beta-carotene and serum and erythrocyte folate were measured. Partial correlations were used in the full model, and weighted kappa coefficients were used to determine agreement between ranking quartiles of dietary intake estimates with corresponding biomarker status quartiles. RESULTS: Serum and dietary intake of alpha-carotene were positively associated in males (p = 0.009) and females (p < 0.001), as was serum and intake of beta-carotene (males, p = 0.002; females, p < 0.001). Alpha-carotene was positively associated with vegetable intake in males (p = 0.02) and beta-carotene with vegetable intake in females (p = 0.003). Serum folate in males (p = 0.002) and erythrocyte folate in females (p = 0.02) were associated with dietary folate intake. In females, the relationships between biomarker and dietary estimates yielded significant kappa coefficients. In males, a significant kappa coefficient was observed for erythrocyte folate and dietary intake of folate only. The kappa coefficient for serum and estimated intake of beta-carotene was not significant in males. CONCLUSION: Twelve-week habitual intake of alpha-and beta-carotene and folate were correlated with circulating biomarkers in a military training population. The 2014 Block FFQ was able to accurately rank females into quartiles of nutrient status based on intake, while males were ranked less accurately than females.

Serum beta-carotene modifies the association between phthalate mixtures and insulin resistance: The National Health and Nutrition Examination Survey 2003-2006.

Animal models suggest a protective role of antioxidants against the adverse effect of di-2-ethylhexyl phthalate (DEHP) on insulin resistance. However, no epidemiologic study has examined the effects observed in the animal model. We conduct a study to examine associations of urinary concentrations of phthalate metabolites (individually and as a mixture) with insulin resistance, along with potential effect modification by serum antioxidant concentrations. This cross-sectional study included 1605 participants (51% males) aged 12-85 from the National Health and Nutrition Examination Surveys (2003-2006). Urinary concentrations of 9 phthalate metabolites were measured from spot urine samples. Antioxidant (vitamin A, C, E, and carotenoids) concentrations were measured from a fasting serum sample. We used Bayesian Kernel Machine Regression (BKMR) to evaluate associations between phthalate metabolite mixtures and insulin resistance, and examined whether serum antioxidant levels modified these associations, while accounting for the correlations of multiple concurrent exposures. A change in urinary ΣDEHP concentrations from the 25th to the 75th percentile was associated with a higher log HOMA-IR of 0.07 (95% CI = 0.01, 0.14) (4.85% increase in HOMA-IR). In contrast, the same change in urinary monoethyl phthalate (MEP) was associated with a lower HOMA-IR of -0.07 (95% CI = -0.14, -0.02) (6.68% decrease in HOMA-IR). The positive association between ΣDEHP and HOMA-IR became weaker at higher concentrations of serum ß-carotene. The relationship between MEP and HOMA-IR, however, was not modified by the serum antioxidants examined. The remaining phthalate metabolites were unrelated to HOMA-IR. In this cross-sectional study, the positive association between DEHP exposure and insulin resistance weakened among participants with higher concentrations of serum ß-carotene. As this is the first human report on the protective role of serum ß-carotene on DEHP induced insulin resistance, future studies are needed.

Low Levels of Serum ß-Carotene and ß-Carotene/Retinol Ratio Are Associated with Histological Severity in Nonalcoholic Fatty Liver Disease Patients.

ß-Carotene has been reported to alleviate hepatic steatosis (SS), inflammation, and fibrosis in vivo and vitro studies. However, the clinical relevance of serum ß-carotene and ß-carotene-to-retinol (SC/SR) ratio with histological severity in nonalcoholic fatty liver disease (NAFLD) patients is unknown. This case-control study enrolled 24 control subjects and 62 NAFLD patients. Liver biopsies were collected and histological characteristics were assessed. Information with regard to demographic, anthropometric and dietary intake was assessed by face-to-face interviews with questionnaire. Serum ß-carotene and retinol concentrations were determined by the HPLC method. Serum ß-carotene and SC/SR levels in NAFLD patients were significantly lower than these in controls (0.23 ± 0.01 vs. 0.35 ± 0.04 µmol/L, 0.38 ± 0.03 vs. 0.84 ± 0.10). Compared with individuals without SS, both ß-carotene and SC/SR levels were significantly decreased in those with moderate SS (0.34 ± 0.03 vs. 0.21 ± 0.02 µmol/L, 0.76 ± 0.09 vs. 0.37 ± 0.05). Subjects with mild inflammation had a significantly lower ß-carotene and SC/SR levels than those without inflammation (0.23 ± 0.01 vs. 0.33 ± 0.04 µmol/L, 0.77 ± 0.09 vs. 0.38 ± 0.03). Serum SC/SR was significantly lower in patients with mild fibrosis than those without fibrosis (0.45 [0.27-0.83] vs. 0.34 [0.26-0.51]). According to the NAFLD Activity Scoring score, both ß-carotene and SC/SR gradually decreased with disease progression from normal liver, simple SS to steatohepatitis borderline (ptrend ≤ 0.001). These results show that NAFLD patients have lower circulating ß-carotene concentration and SC/SR ratio, which are associated with the histological severity of NAFLD.

Vitamin A and ß-carotene in pregnant and breastfeeding post-bariatric women in an urban population.

Background As breastfeeding awareness and social acceptance are increased, maternal nutritional deficiency requires more investigation. Methods A prospective cohort study was conducted to determine if vitamin A deficiency is more common in pregnant, lactating post-bariatric surgery women in an inner city population. Antepartum, women after bariatric surgery and controls with no history of malabsorption were recruited. Third trimester, postpartum maternal blood and cord blood were collected as well as three breast milk samples: colostrum, transitional and mature milk. A nutritional survey of diet was completed. Each serum sample was analyzed for total retinol and ß-carotene; breast milk samples were analyzed for retinol and retinyl esters, total retinol and ß-carotene. Results Fifty-three women after bariatric surgery and 66 controls were recruited. Postpartum serum retinol was significantly higher in women after bariatric surgery in the univariate analysis (P<0.0001) and confirmed in the multiple linear mixed model (P=0.0001). Breast milk colostrum retinol and transitional milk total retinol were significantly greater in the bariatric surgery group in the univariate analysis (P=0.03 and P=0.02, respectively), but not after adjusting for confounders. Serum ß-carotene in the third trimester and postpartum were lower (P<0.0001 and P=0.003, respectively) in the bariatric surgery group but not after adjusting for confounders. Vitamin A deficiency was high in both groups in serum and breast milk samples. Conclusion Nutritional deficiencies in breastfeeding women after bariatric surgeries may in fact be less common than in control women in an inner city.

Technical note: Rapid field test for the quantification of vitamin E, ß-carotene, and vitamin A in whole blood and plasma of dairy cattle.

Fast and easy tests for quantifying fat-soluble vitamins such as vitamin E and vitamin A, as well as ß-carotene, in whole blood without a need to preprocess blood samples could facilitate assessment of the vitamin status of dairy cattle. The objective of this study was to validate a field-portable fluorometer/spectrophotometer assay for the rapid quantification of these vitamins in whole blood and plasma of dairy cows and calves. We measured the concentrations of vitamin E and ß-carotene in whole blood and plasma from 28 dairy cows and 11 calves using the iCheck test (BioAnalyt GmbH, Teltow, Germany) and compared the results with the current analytical standard (HPLC) in 2 independent laboratories, one at the University of Potsdam (Germany) and at one at DSM Nutritional Products Ltd. (Kaiseraugst, Switzerland). For vitamin A, the HPLC measurements were done only in the laboratory in Germany. The whole-blood concentrations of vitamin E as determined by iCheck (blood-hematocrit-corrected) ranged from 1.82 to 4.99 mg/L in dairy cows and 0.34 to 3.40 mg/L in calves. These findings were moderately correlated (R2 = 0.66) with the values assessed by HPLC in dairy cattle (cows + calves). When calves were excluded, the correlation was higher (R2 = 0.961). The ß-carotene and vitamin A values obtained by the reference method HPLC were highly correlated with the iCheck methods in whole blood (R2 = 0.99 and 0.88, respectively). In plasma, we observed strong correlations between the concentrations assessed by iCheck and those of HPLC for vitamin E (R2 = 0.97), ß-carotene (R2 = 0.98), and vitamin A (R2 = 0.92) in dairy cattle (cows + calves). For vitamin E, ß-carotene, and vitamin A, we compared the relationship between the differences obtained by the iCheck assay and the HPLC measurements, as well as the magnitude of measurements, using Bland-Altman plots to test for systematic bias. For all 3 vitamins, the differences values were not outside the 95% acceptability limits; we found no systematic error between the 2 methods for all 3 analytes.

A transformation-based approach to Gaussian mixture density estimation for bounded data.

Finite mixture of Gaussian distributions provide a flexible semiparametric methodology for density estimation when the continuous variables under investigation have no boundaries. However, in practical applications, variables may be partially bounded (e.g., taking nonnegative values) or completely bounded (e.g., taking values in the unit interval). In this case, the standard Gaussian finite mixture model assigns nonzero densities to any possible values, even to those outside the ranges where the variables are defined, hence resulting in potentially severe bias. In this paper, we propose a transformation-based approach for Gaussian mixture modeling in case of bounded variables. The basic idea is to carry out density estimation not on the original data but on appropriately transformed data. Then, the density for the original data can be obtained by a change of variables. Both the transformation parameters and the parameters of the Gaussian mixture are jointly estimated by the expectation-maximization (EM) algorithm. The methodology for partially and completely bounded data is illustrated using both simulated data and real data applications.

Shorter Time to Pregnancy With Increasing Preconception Carotene Concentrations Among Women With 1-2 Previous Pregnancy Losses.

Although maternal nutrition may affect fecundity, associations between preconception micronutrient levels and time to pregnancy (TTP) have not been examined. We assessed the relationship between preconception fat-soluble micronutrient concentrations and TTP among women with 1-2 prior pregnancy losses. This was a prospective cohort study of 1,228 women set within the Effects of Aspirin in Gestation and Reproduction (EAGeR) Trial (United States, 2007-2011), which assessed the association of preconception-initiated daily low-dose aspirin with reproductive outcomes. We measured preconception levels of zeaxanthin, cryptoxanthin, lycopene, α- and ß-carotene, and α- and γ-tocopherol in serum. We used discrete Cox regression models, accounting for left-truncation and right-censoring, to calculate fecundability odds ratios and 95% confidence intervals. The models adjusted for age, body mass index, race, smoking, alcohol, physical activity, income, vitamin use, cholesterol, treatment arm, and study site. Serum α-carotene levels (per log unit (µg/dL) increase, fecundability odds ratio (FOR) = 1.17, 95% confidence interval (CI): 1.00, 1.36) and serum α-carotene concentrations at or above the US average (2.92 µg/dL) versus below the average (FOR = 1.21, 95% CI: 1.02, 1.44) were associated with shorter TTP. Compared with levels below the US average (187 µg/dL), γ-tocopherol concentrations at or above the average were associated with longer TTP (FOR = 0.83, 95% CI: 0.69, 1.00). The potential for these nutrients to influence fecundability deserves further exploration.