Provitamin A Carotenoid-Biofortified Maize Consumption Increases Pupillary Responsiveness among Zambian Children in a Randomized Controlled Trial.
J Nutr
; 146(12): 2551-2558, 2016 Dec.
Article
em En
| MEDLINE
| ID: mdl-27798345
ABSTRACT
BACKGROUND:
Impaired dark adaptation is an early functional indicator of vitamin A deficiency that may be prevented by regular dietary intake of foods containing provitamin A carotenoids.OBJECTIVE:
We tested the impact of provitamin A carotenoid-biofortified maize consumption (â¼15 µg ß-carotene/g) on dark adaptation in Zambian children.METHODS:
We used a cluster-randomized trial of children aged 4-8 y (n = 1024) in Mkushi District, Zambia, and compared the regular consumption (2 meals/d, 6 d/wk for 6 mo) of biofortified orange maize (OM) to white maize (WM). The primary outcome was the serum retinol response. In a random sample (n = 542), we used a digital pupillometer to test pre- and postintervention responses to graded light stimuli (-2.9 to 0.1 log cd/m2) in a dark-adapted state.RESULTS:
At baseline, 11.7% of the children had serum retinol <0.7 µmol/L, 14.4% had impaired dark adaptation (pupillary threshold ≥ -1.11 log cd/m2), and 2.3% had night blindness. The mean ± SD pupillary responsiveness to light stimuli was poorer at baseline in the OM group (16.1% ± 6.6%) than the WM group (18.1% ± 6.4%) (P = 0.02) but did not differ at follow-up (OM 17.6% ± 6.5%; WM 18.3% ± 6.5%). Among children with serum retinol <1.05 µmol/L at baseline, there was greater improvement in pupillary responsiveness in the OM group (2.2%; 95% CI 0.1%, 4.3%) than the WM group (0.2%; 95% CI -1.1%, 1.5%; P = 0.01), but there were no differences in children with adequate baseline status. We found no effect of treatment on pupillary threshold or night blindness.CONCLUSIONS:
The regular consumption of provitamin A carotenoid-biofortified maize increased pupillary responsiveness among children with marginal or deficient vitamin A status, providing evidence of a functional benefit to consuming this biofortified crop. This trial was registered at clinicaltrials.gov as NCT01695148.Palavras-chave
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Base de dados:
MEDLINE
Assunto principal:
Reflexo Pupilar
/
Deficiência de Vitamina A
/
Alimentos Fortificados
/
Beta Caroteno
/
Zea mays
/
Provitaminas
Tipo de estudo:
Clinical_trials
Limite:
Child
/
Child, preschool
/
Female
/
Humans
/
Male
País como assunto:
Africa
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article