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Biofortified orange maize is as efficacious as a vitamin A supplement in Zambian children even on the background of high liver reserves of vitamin A (39.5)
Author(s) -
Gan Bryan,
Kaliwile Chisela,
Arscott Sara,
Schmaelzle Samantha,
Masi Cassim,
Chileshe Justin,
Tanumihardjo Sherry
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.28.1_supplement.39.5
Subject(s) - orange (colour) , biofortification , medicine , placebo , zoology , vitamin , food science , chemistry , biology , micronutrient , alternative medicine , pathology
Biofortification is an emerging strategy to relieve vitamin A (VA) deficiency. Biofortified (orange) maize contains β‐carotene (βC) and has shown efficacy for VA status in animal models, but has yet to be confirmed in humans. A randomized, placebo‐controlled orange maize efficacy trial was conducted in rural Zambia. The paired 13 C‐retinol isotope dilution test, the most accurate and sensitive indirect marker of vitamin A status, was used to measure total body reserves (TBR) of vitamin A before and after a 90‐d intervention period. Treatment arms were white maize with placebo oil (VA‐), white maize with VA oil (VA+), and orange maize with placebo oil (orange). Change in TBR showed a treatment effect ( P = 0.011) with VA+ being significantly greater than VA‐, while orange was statistically similar to both (203 ± 386, ‐4.50 ± 208, 109 ± 341 µmol, respectively). However, data were not normally distributed ( P < 0.0001), medians were VA‐ 12.6, VA+ 97.8, orange 83.7 µmol, and non‐parametric analysis showed VA+ and orange were statistically similar and different from VA‐. Baseline estimates of liver concentration were 1.13 ± 0.41 µmol/g, with 59% > 1 µmol/g, the current sub‐toxicity cutoff. None were < 0.1 µmol/g. The bioconversion factor was calculated to be 10.4 µg βC:µg retinol using the middle three quintiles of change in TBR from each treatment group. Change in serum retinol showed no treatment effect ( P = 0.16). The βC in maize is a very effective vitamin A source when consumed as a staple food and could avoid potential toxicity issues with preformed VA from supplementation or fortification as seen in this population. Further use of stable isotopes should be used to elucidate the VA status of various populations, and serum retinol should be used with caution in setting global health policy. Grant Funding Source : Supported by HarvestPlus and NIH grant T32‐DK007665 (BG)