β-Cryptoxanthin and zeaxanthin are highly bioavailable from whole-grain and refined biofortified orange maize in humans with optimal vitamin A status: a randomized, crossover, placebo-controlled trial

Comparison of Total Body Vitamin A Stores Using Individual versus Population 13C-Natural Abundance of Serum Retinol in Preschool Children and Women Residing in 6 Diverse African Countries

BACKGROUND

Stable isotope techniques using 13C to assess vitamin A (VA) dietary sources, absorption, and total body VA stores (TBSs) require determination of baseline 13C abundance. 13C-natural abundance is approximately 1.1% total carbon, but varies with foods consumed, supplements taken, and food fortification with synthetic retinyl palmitate.

OBJECTIVES

We determined 13C variation from purified serum retinol and the resulting impact on TBSs using pooled data from preschool children in Burkina Faso, Cameroon, Ethiopia, South Africa, Tanzania, and Zambia and Zambian women.

METHODS

Seven studies included children (n = 639; 56 ± 25 mo; 48% female) and one in women (n = 138; 29 ± 8.5 y). Serum retinol 13C-natural abundance was determined using GC-C-IRMS. TBSs were available in 7 studies that employed retinol isotope dilution (RID). Serum CRP and α1-acid-glycoprotein (AGP) were available from 6 studies in children. Multivariate mixed models assessed the impact of covariates on retinol 13C. Spearman correlations and Bland-Altman analysis compared serum and milk retinol 13C and evaluated the impact of using study- or global-retinol 13C estimates on calculated TBSs.

RESULTS

13C-natural abundance (%, median [Q1, Q3]) differed among countries (low: Zambia, 1.0744 [1.0736, 1.0753]; high: South Africa, 1.0773 [1.0769, 1.0779]) and was associated with TBSs, CRP, and AGP in children and with TBSs in women. 13C-enrichment from serum and milk retinol were correlated (r = 0.52; P = 0.0001). RID in children and women using study and global estimates had low mean bias (range, -3.7% to 2.2%), but larger 95% limits of agreement (range, -23% to 37%).

CONCLUSIONS

13C-natural abundance is different among human cohorts in Africa. Collecting this information in subgroups is recommended for surveys using RID. When TBSs are needed on individuals in clinical applications, baseline 13C measures are important and should be measured in all enrolled subjects.

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

BACKGROUND

Measuring vitamin A (VA) status during lactation is required to inform dietary recommendations. Limited data exist on VA stores in women.

OBJECTIVES

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.

METHODS

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.

RESULTS

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 (≤0.10 μmol 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 (≤1.0 μmol/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.

CONCLUSIONS

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.

Bioaccessibility and bioavailability of biofortified food and food products: Current evidence

Biofortification increases micronutrient content in staple crops through conventional breeding, agronomic methods, or genetic engineering. Bioaccessibility is a prerequisite for a nutrient to fulfill a biological function, e.g., to be bioavailable. The objective of this systematic review is to examine the bioavailability (and bioaccessibility as a proxy via in vitro and animal models) of the target micronutrients enriched in conventionally biofortified crops that have undergone post-harvest storage and/or processing, which has not been systematically reviewed previously, to our knowledge. We searched for articles indexed in MEDLINE, Agricola, AgEcon, and Center for Agriculture and Biosciences International databases, organizational websites, and hand-searched studies' reference lists to identify 18 studies reporting on bioaccessibility and 58 studies on bioavailability. Conventionally bred biofortified crops overall had higher bioaccessibility and bioavailability than their conventional counterparts, which generally provide more absorbed micronutrient on a fixed ration basis. However, these estimates depended on exact cultivar, processing method, context (crop measured alone or as part of a composite meal), and experimental method used. Measuring bioaccessibility and bioavailability of target micronutrients in biofortified and conventional foods is critical to optimize nutrient availability and absorption, ultimately to improve programs targeting micronutrient deficiency.

Orange corn diets associated with lower severity of footpad dermatitis in broilers

Footpad dermatitis (FPD), damage and inflammation of the plantar surface of the foot, is of concern for poultry because FPD affects the birds' welfare and production value. Footpad dermatitis is painful and causes costly chicken paw downgrades, carcass condemnations, and reduced live weights. However, a universal preventative has not been found. The hypothesis was that diets containing orange corn, when compared with diets containing yellow or white corn, would reduce the severity of footpad dermatitis in broiler chickens on wet litter. When compared with yellow and white corn, orange corn contains higher quantities of carotenoids, antioxidant pigments, believed to play a role in skin and feather health. This experiment was a randomized block, 3 × 2 factorial design: orange, yellow, and white corn diets with birds raised on wet or dry litter (control group). Female Ross 708 broilers (n = 960) were used to create 4 replicates of each diet x litter treatment combination. Footpads were scored at day 19, 27, 35, and 42, following the Global Animal Partnership standard's 0-2 scale of visual increasing severity: 0 indicates minimal damage and 1 and 2 indicate mild to severe lesions and ulceration, dark papillae, and/or bumble foot. At 42 d of age, birds on the wet litter had greater severity of FPD, scores 1 and 2, compared with the control group (88 vs. 13% respectively; P < 0.0001). At 42 d of age, prevalence of more severe footpad scores, 1 or 2, was lowest on the orange corn diet (33%), followed by white corn (56%) and yellow corn (63%). Birds fed the orange corn diet had higher BW throughout the study (P = 0.004) and had fat pads and livers with higher yellow pigment deposition (P < 0.005). Litter moisture content altered microbiome composition but corn type did not. In conclusion, the main determinant of FPD in this study was exposure to wet litter. When compared with yellow and white corn, orange corn was associated with improved bird growth and reduced severity of footpad dermatitis, especially at later time points.

Carotenoids in Cancer Apoptosis-The Road from Bench to Bedside and Back

An incidence and mortality of cancer are rapidly growing worldwide, especially due to heterogeneous character of the disease that is associated with irreversible impairment of cellular homeostasis and function. Targeting apoptosis, one of cancer hallmarks, represents a potent cancer treatment strategy. Carotenoids are phytochemicals represented by carotenes, xanthophylls, and derived compounds such as apocarotenoids that demonstrate a broad spectrum of anti-cancer effects involving pro-apoptotic signaling through extrinsic and intrinsic pathways. As demonstrated in preclinical oncology research, the apoptotic modulation is performed at post-genomic levels. Further, carotenoids demonstrate additive/synergistic action in combination with conventional oncostatic agents. In addition, a sensitization of tumor cells to anti-cancer conventional treatment can be achieved by carotenoids. The disadvantage of anti-cancer application of carotenoids is associated with their low solubility and, therefore, poor bioavailability. However, this deficiency can be improved by using nanotechnological approaches, solid dispersions, microemulsions or biofortification that significantly increase the anti-cancer and pro-apoptotic efficacy of carotenoids. Only limited number of studies dealing with apoptotic potential of carotenoids has been published in clinical sphere. Pro-apoptotic effects of carotenoids should be beneficial for individuals at high risk of cancer development. The article considers the utility of carotenoids in the framework of 3P medicine.

Biofortified Crops for Combating Hidden Hunger in South Africa: Availability, Acceptability, Micronutrient Retention and Bioavailability

In many poorer parts of the world, biofortification is a strategy that increases the concentration of target nutrients in staple food crops, mainly by genetic manipulation, to alleviate prevalent nutrient deficiencies. We reviewed the (i) prevalence of vitamin A, iron (Fe) and zinc (Zn) deficiencies; (ii) availability of vitamin A, iron and Zn biofortified crops, and their acceptability in South Africa. The incidence of vitamin A and iron deficiency among children below five years old is 43.6% and 11%, respectively, while the risk of Zn deficiency is 45.3% among children aged 1 to 9 years. Despite several strategies being implemented to address the problem, including supplementation and commercial fortification, the prevalence of micronutrient deficiencies is still high. Biofortification has resulted in the large-scale availability of βcarotene-rich orange-fleshed sweet potatoes (OFSP), while provitamin A biofortified maize and Zn and/or iron biofortified common beans are at development stages. Agronomic biofortification is being investigated to enhance yields and concentrations of target nutrients in crops grown in agriculturally marginal environments. The consumer acceptability of OFSP and provitamin A biofortified maize were higher among children compared to adults. Accelerating the development of other biofortified staple crops to increase their availability, especially to the target population groups, is essential. Nutrition education should be integrated with community health programmes to improve the consumption of the biofortified crops, coupled with further research to develop suitable recipes/formulations for biofortified foods.

Mining maize diversity and improving its nutritional aspects within agro-food systems

Agro-food systems are undergoing rapid innovation in the world and the system's continuum is promoted at different scales with one of the main outcomes to improve nutrition of consumers. Consumer knowledge through educational outreach is important to food and nutrition security and consumer demands guide breeding efforts. Maize is an important part of food systems. It is a staple food and together with rice and wheat, they provide 60% of the world's caloric intake. In addition to being a major contributor to global food and nutrition security, maize forms an important part of the culinary culture in many areas of Africa, the Americas, and Asia. Maize genetics are being exploited to improve human nutrition with the ultimate outcome of improving overall health. By impacting the health of maize consumers, market opportunities will be opened for maize producers with unique genotypes. Although maize is a great source of macronutrients, it is also a source of many micronutrients and phytochemicals purported to confer health benefits. The process of biofortification through traditional plant breeding has increased the protein, provitamin A carotenoid, and zinc contents of maize. The objective of this paper is to review the innovations developed and promoted to improve the nutritional profiles of maize and outcomes of the maize agro-food system.

Intake of β-cryptoxanthin with fat-containing food increases β-cryptoxanthin serum level and palmar yellowness in healthy adults

Epidemiological and clinical studies have suggested that β-cryptoxanthin (β-CX) has health benefits in humans. To understand the health benefits of β-CX, it is important to examine its in vivo kinetics and identify a convenient noninvasive biomarker for serum β-CX level. However, to date, there have been few studies of β-CX kinetics in humans. We hypothesized that simultaneous consumption of fat-containing food would stimulate absorption of β-CX. We conducted 2 in vivo kinetics studies, one after a single intake and the other after daily intake of β-CX in healthy adults, to examine whether simultaneous consumption of fat-containing food stimulates absorption of β-CX and whether palmar b* value (yellowness) is a suitable biomarker. After a single intake of 1.1 or 2.2 mg of β-CX, the serum level increased dose-dependently and returned to the baseline level after 14 to 17 days. The simultaneous consumption of fat-containing food enhanced the absorption of β-CX by 1.8-fold. During daily intake of 2.0 mg/day β-CX with fat-containing food for 12 weeks, both serum β-CX level and palmar b* value measured with a colorimeter increased continuously. After intake was halted, both serum β-CX level and palmar b* value decreased. There was a positive correlation between serum β-CX level and palmar b* value during the trial (R = 0.55, P < .001). These results suggest that intake of β-CX with fat-containing food stimulates the absorption of β-CX and increases palmar yellowness.

Liver retinol estimated by 13C-retinol isotope dilution at 7 versus 14 days in Burkinabe schoolchildren

Vitamin A status assessment is not straightforward. Retinol isotope dilution (RID) testing requires time for the tracer dose to mix with the total body stores of vitamin A (TBS). Researchers are interested in shortening the time interval between tracer administration and follow-up blood draws, and in re-examining current assumptions about liver mass for calculation of total liver vitamin A reserves (TLR, in µmol/g liver). Schoolchildren (aged 7–12 years; n = 72) were recruited from one school in Burkina Faso. After a baseline blood draw, 1.0 µmol [14,15]-13C2-retinyl acetate was administered to estimate TBS and TLR by retinol isotope dilution with follow-up blood samples at days 7 and 14. Correlations were determined to evaluate if sampling at day 7 could be used to predict TLR compared with day 14. Liver mass was estimated using body surface area and compared with the currently used assumption of liver weight equivalent to 3% of body weight. (This trial was registered at Pan African Clinical Trial Registry: PACTR201702001947398). Liver mass calculated using body surface area did not differ from the standard assumption of 3% of body weight and yielded similar TLR values. The children in this study had mean TLR (0.67 ± 0.35 µmol/g) in the adequate range, while serum retinol concentrations (0.92 ± 0.33 µmol/L) predicted 25% vitamin A deficiency. TLR values at seven days were highly correlated with, but significantly different from day 14 ( P <  0.0001, r =  0.85) and needed a correction factor added to the equation to yield equivalency. Blood drawing at day 7, using correction factors in the prediction equation and the current assumption of liver mass as 3% of body weight, can be used to estimate TLR in schoolchildren with adequate vitamin A status in 13 C2-RID applications, but further investigations are needed to verify the seven-day predictive equation.

Impact statement

Biomarkers of vitamin A status that reflect the gold standard, i.e. liver biopsy, are available but undergoing refinement to increase accessibility in community-based applications. Retinol isotope dilution testing is one such biomarker. Researchers are interested in decreasing the length of time between isotope administration and follow-up blood draws. This study compared a 7-day blood draw with a 14-day sample. With the simple addition of a correction factor to the prediction equation, the values for total body vitamin A stores were similar, but variation increased with increasing liver reserves. The assumption of 3% of body weight as liver weight in school-aged children was also investigated and confirmed as appropriate in the calculation for total liver vitamin A reserves. Simplifying isotope dilution for population evaluation and building capacity for mass spectrometry analyses are important areas of nutrition development to inform public health programs.