Using Stable Isotope Techniques to Monitor & Assess the Vitamin A Status of Children Susceptible to Infection

The relationship between infections and malnutrition is synergistic, each further compromising the outcome of the other. Malnutrition compromises natural immunity leading to increased susceptibility to infections, more frequent and prolonged disease episodes, and increased severity of disease. Likewise, infections can aggravate or precipitate malnutrition through decreased appetite and food intake, nutrient malabsorption, nutrient loss or increased metabolic needs. Severe malnutrition often masks symptoms and signs of infectious diseases making prompt clinical diagnosis and treatment very difficult. Another issue is that infections (as well as overweight and obesity status) affect nutritional biomarkers making it difficult to assess the real magnitude of some nutritional problems. This is the case of vitamin A. Vitamin A deficiency is defined to be of severe public health importance if 20% or more of a defined population has a serum retinol concentration of less than 0.7 µmol/L.

Study Overview

• Status: Unknown
• Conditions: Assessment of Vitamin A Status of Children
• Intervention / Treatment: Other: Vitamin A supplementation

Detailed Description

Vitamin A is an essential nutrient needed for the visual system, and maintenance of cell function for growth, epithelial integrity, red blood cell production, immunity and reproduction. All infants are born with low stores and depend on vitamin A from breast milk to initially accumulate and maintain adequate stores. Infants of vitamin A depleted women are at greater risk of becoming vitamin A deficient early in life, especially if they are not breast fed. Correcting vitamin A deficiency is addressed by some African countries through vitamin A supplementation of children and food fortification programs. However, assessing vitamin A status, and the effectiveness of government interventions, is challenging in settings where infectious diseases are endemic, as in most African countries. Evaluation of vitamin A status is relatively insensitive when based on changes in serum retinol concentrations, which are homeostatically controlled and negatively affected by subclinical infections. Liver stores of vitamin A, the best indicator of vitamin A status, cannot be routinely evaluated. The isotope dilution technique is the preferred method for determining vitamin A status and assessing the efficacy and effectiveness of intervention programs aimed at improving vitamin A status. It is the only indirect assessment method that provides a quantitative estimate of vitamin A status across the continuum of deficient to excessive stores. Thus, this technique can be used for assessing vitamin A status in populations at risk of excessive status due to exposure to too much vitamin A through combined supplementation and consumption of fortified foods and/or preformed vitamin A-rich foods. The aim of this project is to use nuclear techniques to evaluate vitamin A nutritional status of young children during semi-annual administration of vitamin A supplements, and to assess how this relates to infection status. The IAEA has provided significant support on use of stable isotopes in assessing body composition and breast milk to Member States in Africa, it is now establishing the stable isotope technique to assess vitamin A body stores in Cameroon and Zambia (and additional implementation is possible in Morocco) for use throughout the region. These inputs will be used in this project to provide key information to stakeholders on how vitamin A intervention programs affect vitamin A status in children and how infections affect vitamin A status or validity of stable isotope techniques.

• Study Type: Observational
• Enrollment (Anticipated): 120

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 3 years to 5 years (CHILD)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

The project will include preschool children 3-5 years of age. This age has been selected given the high risk of vitamin A deficiency in young children, as well as national policy for biannual vitamin A supplementation of preschool children. Children younger than 3 will not be included due to the volume of blood needed for biomarker analysis. Recruitment will be done in various settings, including household-level, clinics/hospitals, and childcare centres.

Description

Inclusion Criteria:

• Children will be included if they are in the target age range (3-5 years), are not planning to move from the study area for the duration of the study, and do not have severe illness at the time of enrolment

Exclusion Criteria:

• Exclusion criteria will generally include the following conditions: severe anaemia, severe acute malnutrition, obesity, or clinically defined severe illness, such as dehydration, severe diarrhoea or severe respiratory illness.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
High Vitamin A exposure; There was no intervention	Other: Vitamin A supplementation; Bi annual vitamin A supplementation programme
Low vitamin A exposure; No intervention	Other: Vitamin A supplementation; Bi annual vitamin A supplementation programme

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cross sectional vitamin A status	Vitamin A status determination using stable isotopes	1 year

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Assessment of the presence of clinical infections	Infections	1 year

Collaborators and Investigators

• Sponsor: National Food Technology Research Centre, Botswana
• Collaborators: Netherlands: Ministry of Health, Welfare and Sports; UNICEF; University of Botswana

Study record dates

Study Major Dates

• Study Start (ACTUAL): April 30, 2016
• Primary Completion (ANTICIPATED): December 31, 2017
• Study Completion (ANTICIPATED): December 31, 2018

Study Registration Dates

• First Submitted: June 19, 2017
• First Submitted That Met QC Criteria: June 19, 2017
• First Posted (ACTUAL): June 21, 2017

Study Record Updates

• Last Update Posted (ACTUAL): June 21, 2017
• Last Update Submitted That Met QC Criteria: June 19, 2017
• Last Verified: June 1, 2017

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Infections; Physiological Effects of Drugs; Micronutrients; Vitamins; Vitamin A
• Other Study ID Numbers: RAF 6047

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Data will be shared for pooling purposes as this study is part of a regional project

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No