SNP rs6564851 in the BCO1 Gene Is Associated with Varying Provitamin a Plasma Concentrations but Not with Retinol Concentrations among Adolescents from Rural Ghana.

In sub-Saharan Africa, vitamin A deficiency constitutes a severe health problem despite various supplementation and food fortification programs. Given that the intake of preformed vitamin A from animal products remains low in these countries, an efficient metabolization of plant-based provitamin A carotenoids is essential. Previously, adolescents in rural Ghana have shown high total plasma carotenoid concentrations, while 36% had a vitamin A deficiency (defined as plasma retinol < 0.7 µmol/L). Hence, the aim of this cross-sectional study was to identify the relationships between variants in the ß-carotene 15,15'-oxygenase (BCO1) gene and plasma carotenoid concentrations among 189 15-year-old girls and boys in rural Ghana. BCO1 rs6564851, rs7500996, rs10048138 and PKD1L2 rs6420424, and rs8044334 were typed, and carotenoid concentrations were compared among the different genotypes. G allele carriers of rs6564851 (53%) showed higher plasma carotenoid concentrations than T allele carriers (median (interquartile range): 3.07 (2.17-4.02) vs. 2.59 (2.21-3.50) µmol/L, p-value = 0.0424). This was not explained by differences in socio-demographic or dietary factors. In contrast, no differences in plasma retinol concentrations were observed between these genotypes. Pending verification in independent populations, the low conversion efficiency of provitamin A carotenoids among rs6564851 G allele carriers may undermine existing fortification and supplementation programs to improve the vitamin A status in sub-Saharan Africa.

An energy-restricted high-protein diet supplemented with ß-cryptoxanthin alleviated oxidative stress and inflammation in nonalcoholic fatty liver disease: a randomized controlled trial.

The efficacy of ß-cryptoxanthin (BCX), a high-protein diet (HPD), or both in reducing oxidative stress and inflammation in nonalcoholic fatty liver disease (NAFLD) has never been examined within a randomized controlled trial (RCT). Thus, we aimed to assess the efficacy of an energy-restricted HPD supplemented with BCX in alleviating these conditions in NAFLD in an RCT design. We hypothesized that this combination may improve oxidative stress and inflammation in NAFLD as compared to a standard energy-restricted diet. Ninety-two ultrasonographically confirmed overweight/obese adult NAFLD patients attending an outpatient clinic in Ahvaz, Iran, were recruited for this 12-week, single-center, parallel-group, double-blind RCT from 2017 to 2018. Subjects were randomized into 4 equal groups (n = 23): HPD-BCX (energy-restricted HPD + BCX), HPD (energy-restricted HPD + placebo), BCX (standard energy-restricted diet + BCX), and control (standard energy-restricted diet + placebo). Serum levels of oxidative stress- and inflammation-related markers, as primary outcome measures, were determined at baseline and at the study end point. The 1-way analysis of covariance models in the intention-to-treat population (N = 92) showed that the HPD-BCX group achieved greater 12-week reductions in malondialdehyde, high-sensitivity C-reactive protein, interleukin-6, and total cytokeratin-18 (CK18-M65) but higher increases in total antioxidant capacity and adiponectin compared to the control group (mean differences for malondialdehyde, high-sensitivity C-reactive protein, interleukin-6, total cytokeratin-18, total antioxidant capacity, and adiponectin were -1.9 nmol/mL, -1.0 mg/L, -2.0 ng/L, -270.9 ng/L, 2.5 U/mL, and 1.9 mg/L, respectively; all P < .001). These results show that an energy-restricted HPD supplemented with BCX more efficaciously alleviates oxidative stress and inflammation in NAFLD as compared to a standard energy-restricted diet.

ß-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.

Background: Biofortification of staple crops with ß-carotene is a strategy to reduce vitamin A deficiency, and several varieties are available in some African countries. ß-Cryptoxanthin (BCX)-enhanced maize is currently in field trials. To our knowledge, maize BCX bioavailability has not been assessed in humans. Serum retinol 13C content and xanthophyll concentrations are proposed effectiveness biomarkers for biofortified maize adoption. Objective: We determined the relative difference in BCX and zeaxanthin bioavailability from whole-grain and refined BCX-biofortified maize during chronic feeding compared with white maize and evaluated short-term changes in 13C-abundance in serum retinol. Design: After a 7-d washout, 9 adults (mean ± SD age: 23.4 ± 2.3 y; 5 men) were provided with muffins made from BCX-enhanced whole-grain orange maize (WGOM), refined orange maize (ROM), or refined white maize (RWM) for 12 d in a randomized, blinded, crossover study followed by a 7-d washout. Blood was drawn on days 0, 3, 6, 9, 12, 15, and 19. Carotenoid areas under the curve (AUCs) were compared by using a fixed-effects model. 13C-Abundance in serum retinol was determined by using gas chromatography/combustion/isotope-ratio mass spectrometry on days 0, 12, and 19. Vitamin A status was determined by 13C-retinol isotope dilution postintervention. Results: The serum BCX AUC was significantly higher for WGOM (1.70 ± 0.63 µmol ⋅ L-1 ⋅ d) and ROM (1.66 ± 1.08 µmol ⋅ L-1 ⋅ d) than for RWM (-0.06 ± 0.13 µmol ⋅ L-1 ⋅ d; P < 0.003). A greater increase occurred in serum BCX from WGOM muffins (131%) than from ROM muffins (108%) (P ≤ 0.003). Zeaxanthin AUCs were higher for WGOM (0.94 ± 0.33) and ROM (0.96 ± 0.47) than for RWM (0.05 ± 0.12 µmol ⋅ L-1 ⋅ d; P < 0.003). The intervention did not affect predose serum retinol 13C-abundance. Vitamin A status was within an optimal range (defined as 0.1-0.7 µmol/g liver). Conclusions: BCX and zeaxanthin were highly bioavailable from BCX-biofortified maize. The adoption of BCX maize could positively affect consumers' BCX and zeaxanthin intakes and associated health benefits. This trial is registered at www.clinicaltrials.gov as NCT02800408.

Short-Term Daily Consumption of Provitamin A Carotenoid-Biofortified Maize Has Limited Impact on Breast Milk Retinol Concentrations in Zambian Women Enrolled in a Randomized Controlled Feeding Trial.

BACKGROUND: Provitamin A carotenoid-biofortified maize is a conventionally bred staple crop designed to help prevent vitamin A deficiency. Lactating women are a potential target group, because regularly eating biofortified maize may increase vitamin A in breast milk-a critical source of vitamin A for breastfeeding infants. OBJECTIVE: We assessed whether daily consumption of biofortified orange maize would increase the retinol concentration in the breast milk of Zambian women. METHODS: Lactating women (n = 149) were randomly assigned to receive orange maize delivering 600 µg retinol equivalents (REs)/d as carotenoid plus placebo (OM), low-carotenoid white maize plus 600 µg REs/d as retinyl palmitate (VA), or white maize plus placebo (WM). Boiled maize (287 g dry weight/d) was served as 2 meals/d, 6 d/wk for 3 wk. We measured initial and final breast milk plasma retinol and ß-carotene concentrations, and plasma inflammatory protein concentrations. RESULTS: Groups were comparable at enrollment, with an overall geometric mean milk retinol concentration of 0.95 µmol/L (95% CI: 0.86, 1.05 µmol/L); 56% of samples had milk retinol <1.05 µmol/L. Median capsule and maize intake was 97% and 258 g dry weight/d, respectively. Final milk ß-carotene did not vary across groups (P = 0.76). Geometric mean (95% CI) milk retinol concentration tended to be higher in the OM [1.15 µmol/L (0.96, 1.39 µmol/L)] and VA [1.17 µmol/L (0.99, 1.38 µmol/L)] groups than in the WM group [0.91 µmol/L (0.72, 1.14 µmol/L); P = 0.13], and the proportion of women with milk retinol <1.05 µmol/L was 52.1%, 42.9%, and 36.7% in the WM, OM, and VA groups, respectively (P-trend = 0.16). CONCLUSIONS: Daily biofortified maize consumption did not increase mean milk retinol concentration in lactating Zambian women; however, there was a plausible downward trend in the risk of low milk retinol across intervention groups. This trial was registered at clinicaltrials.gov as NCT01922713.

Provitamin A-biofortified maize increases serum ß-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 ß-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-km(2) 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, ß-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 ß-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 ß-carotene concentrations but did not improve serum retinol. This trial was registered at clinicaltrials.gov as NCT01695148.