Vitamin A Supplementation at Birth and Atopy in Childhood

Study Overview
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Brief Summary
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INTRODUCTION Eight trials studying the effect of providing neonatal vitamin A supplementation (NVAS) have been reported, and another four are underway to test whether NVAS should become WHO policy. Three of the four African trials were conducted by the Bandim Health Project (BHP) in Guinea-Bissau. One of them was a two-by-two factorial trial among low-birth-weight children. From 2004-2008, the children were randomly allocated to 25,000 IU vitamin A or placebo at birth, and furthermore to BCG vaccination at birth or later as is local policy. In 2011, the investigators conducted a follow-up study. A remarkably strong harmful effect of NVAS on atopy and wheezing was found (manuscript under review). Seen in the context that NVAS may soon become a WHO policy it is obviously worrying if NVAS is associated with a higher risk of atopy and wheezing. The investigators therefore aim to conduct a similar follow-up study of participants in the first NVAS trial conducted in Guinea-Bissau from 2002-2004, among normal-birth-weight infants, to test whether NVAS is associated with an increased risk of atopy and wheezing and other allergic symptoms as well as growth. METHODS Study population: From 2002-2004 BHP conducted a randomised trial of NVAS. The investigators recruited newborns when they came for BCG vaccination. Provided parental consent, they received an oral supplement of 50,000 IU vitamin A or placebo. Study design: This study will be a follow-up study of the cohort of children randomised to NVAS (intervention) or placebo (current policy) together with BCG vaccine at birth. Other exposures: The investigators will also investigate the effect of receiving an additional dose of measles vaccine and the timing of DTP vaccine on the development of atopy. Assessment of outcomes: The investigators will visit all children at the last known address. Height, weight and mid upper arm circumference will be measured. BCG scar will be examined and vaccination card details recorded by the field assistant. Children will be excluded from skin prick testing (SPT) if they have a history suggestive of anaphylaxis or are currently using anti-histamine medication. SPT will be performed using aero-allergens, food allergens and positive histamine and negative saline control. The mother or guardian will be interviewed by a local assistant. Symptoms of eczema and asthma as well as food allergy will be assessed. Statistical analysis: Effect of randomisation group and other factors on outcomes will be analysed in multivariable regression models. All analyses will be adjusted for skin prick tester. All analyses will be conducted stratified by sex.

Official Title
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The Effect of Vitamin A Supplementation at Birth on the Development of Atopy in Childhood: Long-term Follow-up of a Randomised Placebo-controlled Trial

Conditions
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Asthma, Atopy, Eczema, Food Allergy

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Enrolled at birth in NCT00168610 Exclusion Criteria: Children with history suggestive of anaphylaxis will be excluded from skin prick testing but included in the study population

Ages Eligible for Study
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Minimum Age: 8 Years
Maximum Age: 12 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Atopic sensitisation | Skin prick test positivity. A wheal >=3mm will be considered positive. | Single observation on day of recruitment | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Symptoms of asthma | Questionnaire based on ISAAC survey for 6-7 year olds | Single observation on day of recruitment | 
| Symptoms of eczema | Questionnaire based on ISAAC survey for 6-7 year olds | Single observation on day of recruitment | 
| Symptoms of food allergy | Questionnaire based on Health Nuts survey | Single observation of day of recruitment | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Vitamin A supplementation, BCG vaccination, diphtheria-tetanus-pertussis vaccination, measles vaccination, atopy