Assessment of vitamin A status with the relative-dose-response test in
Peruvian children recovering from pneumonia1,2,3
Charles B Stephensen, Luis Miguel Franchi,
Herminio Hernandez, Miguel Campos, Ana Colarossi,
Robert H Gilman and Jose O Alvarez
1 From the Department of Epidemiology and
International Health, School of Public Health, University of Alabama at
Birmingham (CBS and JOA); the Departments of Pediatrics (LMF and HH),
Mathematics (MC), Physiologic Sciences (AC), and Pathology (RHG), Universidad
Peruana Cayetano Heredia, Lima, Peru; the Department of International Health,
School of Public Health, Johns Hopkins University, Baltimore (RHG); and AB
PRISMA, Lima, Peru (RHG).
Background: The relative-dose-response (RDR) test is used toidentify subjects with marginal liver vitamin A stores, butits
use has not been evaluated during episodes of infection.
Objective: The objective was to assess, with the RDR test, thevitamin A status of children recovering from pneumonia.
Design: As part of a double-blind, placebo-controlled clinicaltrial of high-dose vitamin A supplements among children hospitalizedwith pneumonia in Lima, Peru, we examined the association of
treatment group, nutritional status, severity of disease, and
induction of the acute phase response [on the basis of serum
C-reactive protein (CRP)] on serum retinol and the RDR test.
Results: Serum retinol was low at admission and increased
significantlyin both the vitamin A and placebo groups during
recovery. SerumCRP had a significant, inverse association with
retinol at bothadmission and discharge. Serum retinol and CRP
concentrationsnever differed significantly between the treatment
groups. Amongsubjects with CRP
10 mg/L, 21% in the vitamin A group and
20%in the placebo groups (P = 0.83) had a positive RDR test
result.Among subjects with CRP <10 mg/L, 56% in the placebo groupbut only 6% in the vitamin A group had positive RDR test results(P = 0.002).
Conclusion: The RDR test was useful in assessing the vitaminA status of children recovering from pneumonia when CRP concentrationswere <10 mg/L but not when CRP concentrations were higher.
Key Words: Vitamin A retinol acute phase response
pneumonia C-reactive protein CRP relative-dose-response test RDR test
children Peru
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