Comparison of Vision Restoration Time With Vitamin A Levels in Pregnant Nigerian Women

Abstract

Background: Vitamin A deficiency, subclinical or otherwise is associated with adverse maternal fetal and neonatal outcome, ditto excess vitamin A. The challenge in pregnancy is to detect subclinical vitamin A deficiency in patients for whom supplements or dietary manipulation will be of benefit.

Objective: To compare the usefulness of the vision restoration time with biochemical methods in the determination of vitamin A status in pregnancy.

Study Design And Setting: A cross sectional case controlled study in a University teaching hospital.

Methods: Data was collected from Antenatal patients (142). Using serum Biochemistry three categories of patients were recognised. Patients with normal vitamin A levels (N = 100 with blood vitamin A within two standard deviation of the mean) Twenty four patient (24) had low vitamin A levels (blood vitamin A level at less than 2 standard deviation below the mean). Eighteen patients (18) had high vitamin A levels (blood vitamin A levels at greater than two standard deviation above the mean).

Outcome Measures: The vision restoration time was compared for all three groups of patients.

Results: The vision restoration time (VRT) was found to have a high degree of sensitivity (80%) and a high specificity (83%) in detection of patients with vitamin A deficiency. The positive predictive value was 90% with a negative predictive value of 83%. The VRT was unable however to differentiate patients with normal and high vitamin A.

Conclusion: The vision Restoration time is a cheap effective method to detect subclinical vitamin A deficiency in pregnancy. It is an easy cost effective screening tool to select patients for whom dietary manipulation and or vitamin A supplementation will be beneficial.

Key Words: Vitamin A, Nutrition, Supplementation Pregnancy, Vision

[Trop J Obstet Gynaecol, 2004;21:7-10]