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. uri icon

abstract

  • Background: Biofortification of staple crops with beta-carotene is a strategy to reduce vitamin A deficiency, and several varieties are available in some African countries. beta-Cryptoxanthin (BCX)-enhanced maize is currently in field trials. To our knowledge, maize BCX bioavailability has not been assessed in humans. Serum retinol C-13 content and xanthophyll concentrations are proposed effectiveness biomarkers for biofortified maize adoption.
  • 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.
  • 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. C-13-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 C-13-retinol isotope dilution postintervention.
  • 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 C-13-abundance in serum retinol.
  • Results: The serum BCX AUC was significantly higher for WGOM (1.70 +/- 0.63 mu mol . L-1 . d) and ROM (1.66 +/- 1.08 mu mol . L-1 . d) than for RWM (-0.06 +/- 0.13 mu mol . 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 mu mol . L-1. d; P < 0.003). The intervention did not affect predose serum retinol C-13-abundance. Vitamin A status was within an optimal range (defined as 0.1-0.7 mu mol/g liver).

publication date

  • 2018
  • 2018