Serum carotenoid concentrations and their reproducibility in children in Belize

Transcriptome regulation of carotenoids in five flesh-colored watermelons (Citrullus lanatus)

BACKGROUND

Fruit flesh color in watermelon (Citrullus lanatus) is a great index for evaluating the appearance quality and a key contributor influencing consumers' preferences. But the molecular mechanism of this intricate trait remains largely unknown. Here, the carotenoids and transcriptome dynamics during the fruit development of cultivated watermelon with five different flesh colors were analyzed.

RESULTS

A total of 13 carotenoids and 16,781 differentially expressed genes (DEGs), including 1295 transcription factors (TFs), were detected in five watermelon genotypes during the fruit development. The comprehensive accumulation patterns of carotenoids were closely related to flesh color. A number of potential structural genes and transcription factors were found to be associated with the carotenoid biosynthesis pathway using comparative transcriptome analysis. The differentially expressed genes were divided into six subclusters and distributed in different GO terms and metabolic pathways. Furthermore, we performed weighted gene co-expression network analysis and predicted the hub genes in six main modules determining carotenoid contents. Cla018406 (a chaperone protein dnaJ-like protein) may be a candidate gene for β-carotene accumulation and highly expressed in orange flesh-colored fruit. Cla007686 (a zinc finger CCCH domain-containing protein) was highly expressed in the red flesh-colored watermelon, maybe a key regulator of lycopene accumulation. Cla003760 (membrane protein) and Cla021635 (photosystem I reaction center subunit II) were predicted to be the hub genes and may play an essential role in yellow flesh formation.

CONCLUSIONS

The composition and contents of carotenoids in five watermelon genotypes vary greatly. A series of candidate genes were revealed through combined analysis of metabolites and transcriptome. These results provide an important data resource for dissecting candidate genes and molecular basis governing flesh color formation in watermelon fruit.

High provitamin A carotenoid serum concentrations, elevated retinyl esters, and saturated retinol-binding protein in Zambian preschool children are consistent with the presence of high liver vitamin A stores

BACKGROUND

Biomarkers of micronutrient status are needed to best define deficiencies and excesses of essential nutrients.

OBJECTIVE

We evaluated several supporting biomarkers of vitamin A status in Zambian children to determine whether any of the biomarkers were consistent with high liver retinol stores determined by using retinol isotope dilution (RID).

DESIGN

A randomized, placebo-controlled, biofortified maize efficacy trial was conducted in 140 rural Zambian children from 4 villages. A series of biomarkers were investigated to better define the vitamin A status of these children. In addition to the assessment of total-body retinol stores (TBSs) by using RID, tests included analyses of serum carotenoids, retinyl esters, and pyridoxal-5'-phosphate (PLP) by using high-pressure liquid chromatography, retinol-binding protein by using ELISA, and alanine aminotransferase (ALT) activity by using a colorimetric assay.

RESULTS

Children (n = 133) were analyzed quantitatively for TBSs by using RID. TBSs, retinyl esters, some carotenoids, and PLP differed by village site. Serum carotenoids were elevated above most nonintervened reference values for children. α-Carotene, β-carotene, and lutein values were >95th percentile from children in the US NHANES III, and 13% of children had hypercarotenemia (defined as total carotenoid concentration >3.7 μmol/L). Although only 2% of children had serum retinyl esters >10% of total retinol plus retinyl esters, 16% of children had >5% as esters, which was consistent with high liver retinol stores. Ratios of serum retinol to retinol-binding protein did not deviate from 1.0, which indicated full saturation. ALT activity was low, which was likely due to underlying vitamin B-6 deficiency, which was confirmed by very low serum PLP concentrations.

CONCLUSIONS

The finding of hypervitaminosis A in Zambian children was supported by high circulating concentrations of carotenoids and mildly elevated serum retinyl esters. ALT-activity assays may be compromised with co-existing vitamin B-6 deficiency. Nutrition education to improve intakes of whole grains and animal-source foods may enhance vitamin B-6 status in Zambians.

Relationship of serum carotenoids and retinol with anaemia among pre-school children in the northern mountainous region of Vietnam

Objective

To characterize the relationship between serum carotenoids, retinol and anaemia among pre-school children.

Design

A cross-sectional study was conducted in two groups: anaemic and non-anaemic. Serum levels of retinol, α-carotene, β-carotene, β-cryptoxanthin, lycopene, lutein and zeaxanthin were measured in the study subjects.

Setting

Six rural communes of Dinh Hoa, a rural and mountainous district in Thai Nguyen Province, in the northern mountainous region of Vietnam.

Subjects

A total of 682 pre-school children, aged 12–72 months, were recruited.

Results

Geometric mean serum concentrations of carotenoids (μmol/l) were 0·056 for α-carotene, 0·161 for β-carotene, 0·145 for β-cryptoxanthin, 0·078 for lycopene, 0·388 for lutein and 0·075 for zeaxanthin. The mean levels of Hb and serum retinol were 108·8 g/l and 1·02 μmol/l, respectively. The prevalence of anaemia and vitamin A deficiency was 53·7 % and 7·8 %, respectively. After adjusting for sex and stunting, serum retinol concentrations (μmol/l; OR = 2·06, 95 % CI 1·10, 3·86, P = 0·024) and total provitamin A carotenoids (μmol/l; OR = 1·52, 95 % CI 1·01, 2·28, P = 0·046) were independently associated with anaemia, but non-provitamin A carotenoids (μmol/l; OR = 0·93, 95 % CI 0·63, 1·37, P = 0·710) were not associated with anaemia.

Conclusions

Among pre-school children in the northern mountainous region of Vietnam, the prevalences of vitamin A deficiency and anaemia are high, and serum retinol and provitamin A carotenoids are independently associated with anaemia. Further studies are needed to determine if increased consumption of provitamin A carotenoids will reduce anaemia among pre-school children.

Short-term beta-carotene supplementation of lactating mothers consuming diets low in vitamin A

We have previously shown that beta-carotene supplementation of the diets of healthy U.S. mothers increases serum and milk beta-carotene concentrations. Building on these results, we investigated the possibility that beta-carotene supplementation could enhance the vitamin A status of mothers and their nursing infants. Three 30-mg doses of beta-carotene were administered on 3 consecutive days to 44 lactating mothers who had vitamin-A-poor diets. Concentrations of maternal serum and milk carotenoids and retinol were evaluated at baseline and after 2 and 3 days of supplementation. Infant serum carotenoids and retinol were measured at baseline and 2 days following maternal supplementation. beta-Carotene supplementation markedly elevated maternal serum and milk beta-carotene concentrations (nine- and sevenfold, respectively) and resulted in smaller, transient increases of alpha-carotene, lycopene, and beta-cryptoxanthin concentrations in maternal serum. Maternal serum and milk retinol were unchanged in response to the treatment. In contrast, maternal beta-carotene supplementation significantly increased infant serum retinol (P </= 0.001) and beta-carotene concentrations remained unchanged. These results imply that breast milk beta-carotene can supply retinol for the nursing infant. Further research is needed to identify the site of bioconversion of milk-derived beta-carotene to retinol and to describe the factors that regulate this process.

Serum concentrations of retinol, alpha-tocopherol and the carotenoids are influenced by diet, race and obesity in a sample of healthy adolescents

An important part of understanding the functions of vitamin A, vitamin E and the carotenoids in nutritional status assessment, health promotion and disease prevention is knowledge of factors that influence their distribution in human tissues. Our objective was to examine serum concentrations of these nutrients and compounds in a sample of 285 healthy participants, 12-17 y old, from three U. S. cities. Pearson correlations between diet measured with a food frequency questionnaire and serum nutrient concentrations among these adolescents (adjusted for total serum cholesterol, age, sex, race and body mass index) were as follows: retinol, 0.23; alpha-tocopherol, 0.16; alpha-carotene, 0.31; beta-carotene, 0.15; beta-cryptoxanthin, 0.38; lycopene, 0.08; and lutein + zeaxanthin, 0.25. Multivariate linear regression modeled associations of demographic, dietary and physiologic variables with serum concentrations of these nutrients. African-American participants had significantly lower concentrations of serum retinol (P < 0.001), alpha-tocopherol (P < 0.01) and alpha-carotene (P < 0.02), but higher concentrations of lutein + zeaxanthin (P = 0.001) compared with Caucasians. Obese participants had serum nutrient concentrations that were 2-10% (P < 0.05) lower than normal weight participants. Dietary intake was a significant predictor of all serum analytes (P < 0.01) except lycopene. These models explained 20% of the variability in serum retinol, 28% of the variability in serum alpha-tocopherol, and 14-24% of the variability in serum carotenoids.

Relation of vitamin A and carotenoid status to growth failure and mortality among Ugandan infants with human immunodeficiency virus

Although growth failure is common during pediatric infection with human immunodeficiency virus (HIV) and associated with increased mortality, the relation of specific nutrition factors with growth and mortality has not been well characterized. A longitudinal study was conducted with 194 HIV-infected infants in Kampala, Uganda. Plasma vitamin A, carotenoids (alpha-carotene, beta-carotene, beta-cryptoxanthin, lycopene, and lutein/zeaxanthin), and vitamin E were measured at age 14 wk, and weight and height were followed up to age 12 mo. Vitamin A and low plasma carotenoid concentrations were predictive of decreased weight and height velocity. Between ages 14 wk and 12 mo, 32% of infants died. Underweight, stunting, and low concentrations of plasma carotenoids were associated with increased risk of death in univariate analyses. Plasma vitamin A concentrations were not associated with risk of death. In a final multivariate model adjusting for weight-for-age, plasma beta-carotene was significantly associated with increased mortality (odds ratio: 3.16, 95% confidence interval: 1.38 to 7.21, P < 0.006). These data suggest that low concentrations of plasma carotenoids are associated with increased risk of death during HIV infection among infants in Uganda.

Lycopene: chemistry, biology, and implications for human health and disease

A diet rich in carotenoid-containing foods is associated with a number of health benefits. Lycopene provides the familiar red color to tomato products and is one of the major carotenoids in the diet of North Americans and Europeans. Interest in lycopene is growing rapidly following the recent publication of epidemiologic studies implicating lycopene in the prevention of cardiovascular disease and cancers of the prostate or gastrointestinal tract. Lycopene has unique structural and chemical features that may contribute to specific biological properties. Data concerning lycopene bioavailability, tissue distribution, metabolism, excretion, and biological actions in experimental animals and humans are beginning to accumulate although much additional research is necessary. This review will summarize our knowledge in these areas as well as the associations between lycopene consumption and human health.