Assessment of vitamin A status with the relative-dose-response test in Peruvian children recovering from pneumonia.
BACKGROUND
The relative-dose-response (RDR) test is used to identify subjects with marginal liver vitamin A stores, but its use has not been evaluated during episodes of infection.


OBJECTIVE
The objective was to assess, with the RDR test, the vitamin A status of children recovering from pneumonia.


METHODS
As part of a double-blind, placebo-controlled clinical trial of high-dose vitamin A supplements among children hospitalized with 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 significantly in both the vitamin A and placebo groups during recovery. Serum CRP had a significant, inverse association with retinol at both admission and discharge. Serum retinol and CRP concentrations never differed significantly between the treatment groups. Among subjects with CRP > or =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 group but only 6% in the vitamin A group had positive RDR test results (P = 0.002).


CONCLUSIONS
The RDR test was useful in assessing the vitamin A status of children recovering from pneumonia when CRP concentrations were <10 mg/L but not when CRP concentrations were higher.
Stephensen
Charles B
CB
Department of Epidemiology and International Health, School of Public Health, University of Alabama at Birmingham, USA. cstephensen@ucdavis.udu
Franchi
Luis Miguel
LM
Hernandez
Herminio
H
Campos
Miguel
M
Colarossi
Ana
A
Gilman
Robert H
RH
Alvarez
Jose O
JO
D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D002097:C-Reactive Protein / Q000032:analysis; D002675:Child, Preschool; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009752:Nutritional Status; D010568:Peru; D010919:Placebos; D018410:Pneumonia, Bacterial / Q000097:blood / Q000628:therapy*; D011024:Pneumonia, Viral / Q000097:blood / Q000628:therapy*; D014801:Vitamin A / Q000008:administration & dosage* / Q000097:blood*; D014802:Vitamin A Deficiency / Q000175:diagnosis
D000900:Anti-Bacterial Agents; D010919:Placebos; D014801:Vitamin A; D002097:C-Reactive Protein