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Detection of vitamin A deficiency in Brazilian preschool children using the serum 30-day dose-response test
I S Ferraz1, J C Daneluzzi, H Vannucchi
1Department of Child Care and Pediatrics, University of São Paulo, Ribeirão Preto, Brazil. isferraz@uol.com.br
Insights
Subclinical Vitamin A deficiency (VAD) is common in Brazilian children. The serum 30-day dose-response test (+S30DR) effectively identifies this condition, offering a valuable community assessment tool.
Area of Science:
- Nutritional Science
- Pediatric Health
- Public Health
Background:
- Vitamin A deficiency (VAD) is prevalent in Brazil, posing diagnostic challenges for health professionals.
- Serum retinol levels may not accurately reflect an individual's vitamin A status.
- Subclinical VAD is difficult to recognize without specialized testing.
Purpose of the Study:
- To identify subclinical Vitamin A deficiency (VAD) in preschool children using the serum 30-day dose-response test (+S30DR).
- To evaluate the efficacy of the +S30DR test as a community-level assessment tool for vitamin A status.
Main Methods:
- A prospective study involving 188 preschool children.
- Measurement of serum retinol concentrations before and after vitamin A supplementation (200,000 IU).
- Calculation of the +S30DR value to assess vitamin A status, alongside clinical and anthropometric evaluations.
Main Results:
- A high prevalence of VAD was indicated, with 74.5% of children showing +S30DR values suggesting low hepatic vitamin A reserves.
- Serum retinol concentrations were significantly lower before supplementation.
- No cases of xerophthalmia were observed, and malnutrition affected 3.7% of the children; fever/diarrhea did not impact +S30DR results.
Conclusions:
- The study identified a significant prevalence of subclinical Vitamin A deficiency in the studied preschool population.
- +S30DR test is a reliable indicator for assessing subclinical VAD in children in resource-limited settings.
- The +S30DR test shows promise as a practical tool for community-based vitamin A status assessment.
Background:
Vitamin A deficiency (VAD) is endemic in Brazil and health professionals have difficulty in recognizing its subclinical form. In addition, serum retinol concentrations do not always represent vitamin A status in the organism.
Objective:
To identify VAD in preschool children by the serum 30-day dose-response test (+S30DR) and to examine its potential as a tool for the assessment of vitamin A status in the community.
Design:
A prospective transverse study in which blood samples were obtained from 188 preschool children for the determination of serum retinol concentrations and the children were submitted to ocular inspection and anthropometric measurements. Information about the presence of diarrhea and/or fever during the 15 days preceding the study was also obtained. The children received an oral dose of 200,000 IU vitamin A immediately after the first blood collection. A second blood sample was obtained 30-45 days after supplementation in order to determine the +S30DR.
Results:
In all, 74.5% (140/188; 95% confidence interval: 68.3-80.7%) of the children presented +S30DR values indicative of low hepatic reserves. The mean serum retinol concentration was significantly lower before supplementation (0.92 and 1.65 micromol/l, respectively; P < 0.0001). No child presented xerophthalmia; 3.7% (7/188) of the children were malnourished. The presence of fever and/or diarrhea during the 15 days preceding the first blood collection did not affect the +S30DR value.
Conclusions:
The prevalence of VAD in the study group was elevated. +S30DR proved to be a good indicator of subclinical VAD in children from an underdeveloped country.
