Neonatal vitamin A supplementation associated with increased atopy in girls.
BACKGROUND
Neonatal vitamin A supplementation (NVAS) is currently being considered as policy in countries at risk of deficiency. A previous study suggested that NVAS may be associated with increased atopy. We examined the effect of NVAS on atopy by conducting long-term follow-up of a previous randomized controlled trial in Guinea-Bissau.


METHODS
In 2002-2004, we randomized 4345 normal birthweight neonates to NVAS (50 000 IU retinyl palmitate) or placebo together with their Bacillus Calmette-Guérin vaccination. In 2013, we visited the 1692 (39%) children now aged 8-10 years who were still living in the study area, and 1478 (87%) were found at home. Provided consent, a skin prick test was performed, and history of allergic symptoms was recorded. Associations of NVAS and atopy (defined as skin prick test reaction of ≥3 mm) were analysed using binomial regression.


RESULTS
Of the 1430 children with a valid skin prick test, 228 (16%) were positive (more boys (20%) than girls (12%), P-value < 0.0001). NVAS did not increase the overall risk of atopy (RR 1.10 [95% CI 0.87-1.40]). However, NVAS was associated with significantly increased risk among females (RR 1.78 [1.17-2.72]) but not among males (0.86 [0.64-1.15], P-value for interaction between NVAS and gender = 0.005). Furthermore, NVAS was associated with increased risk of wheezing among females (RR 1.80 [1.03-3.17], but not among males, P-value for interaction = 0.05).


CONCLUSIONS
The study corroborated previous observations; NVAS was associated with increased risk of atopy and wheezing, in this study only among females. Further studies on NVAS and atopy are warranted.
Bandim Health Project, Bissau, Guinea-Bissau.|Research Center for Vitamins and Vaccines (CVIVA), Statens Serum Institut, Copenhagen S, Denmark.
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Aage
Gastro and Food Allergy Research Group, Murdoch Children's Research Institute, Parkville, Vic., Australia.
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Kiraly
Bandim Health Project, Bissau, Guinea-Bissau.
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Da Costa
Bandim Health Project, Bissau, Guinea-Bissau.|Research Center for Vitamins and Vaccines (CVIVA), Statens Serum Institut, Copenhagen S, Denmark.|OPEN, Institute of Clinical Research, University of Southern Denmark/Odense University Hospital, Odense C, Denmark.
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Byberg
Bandim Health Project, Bissau, Guinea-Bissau.|Research Center for Vitamins and Vaccines (CVIVA), Statens Serum Institut, Copenhagen S, Denmark.
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Bjerregaard-Andersen
Bandim Health Project, Bissau, Guinea-Bissau.|Research Center for Vitamins and Vaccines (CVIVA), Statens Serum Institut, Copenhagen S, Denmark.
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Fisker
Bandim Health Project, Bissau, Guinea-Bissau.|Research Center for Vitamins and Vaccines (CVIVA), Statens Serum Institut, Copenhagen S, Denmark.
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Aaby
Bandim Health Project, Bissau, Guinea-Bissau.|Research Center for Vitamins and Vaccines (CVIVA), Statens Serum Institut, Copenhagen S, Denmark.|OPEN, Institute of Clinical Research, University of Southern Denmark/Odense University Hospital, Odense C, Denmark.
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Benn
D017677:Age Distribution; D001500:BCG Vaccine / Q000008:administration & dosage; D002648:Child; D003906:Developing Countries; D019587:Dietary Supplements / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D006169:Guinea-Bissau; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000453:epidemiology* / Q000209:etiology*; D015994:Incidence; D007231:Infant, Newborn; D008297:Male; D018570:Risk Assessment; D017678:Sex Distribution; D012882:Skin Tests / Q000379:methods; D014611:Vaccination / Q000379:methods; D014801:Vitamin A / Q000008:administration & dosage* / Q000009:adverse effects*
D001500:BCG Vaccine; D014801:Vitamin A
Guinea-Bissau; allergy; immunology; vitamin A; wheezing