Vitamin A status in pregnant women in Iran in 2001 and its relationship with province and gestational age

Abstract

BackgroundVitamin A deficiency is considered as one of the public health problems among pregnant women worldwide. Population representative data on vitamin A status in pregnancy have not previously been published from Iran.ObjectivesThe aim of this study was to publish data on vitamin A status in pregnant women in all the provinces of Iran in 2001, including urban and rural areas, and to describe the association of vitamin A status with maternal age, gestational age, and parity.DesignThis descriptive cross-sectional study was conducted on 3,270 healthy pregnant women from the entire country, 2,631 with gestational age ≤36 weeks, and 639 with gestational age >36 weeks. Vitamin A status was determined in serum using high-performance liquid chromatography.ResultRetinol levels corresponding to deficiency were detected in 6.6% (<0.36 µmol/L) and 18% had insufficient vitamin A levels (≥0.36–<0.7 µmol/L). Suboptimal level of serum retinol was observed in 55.3% of the pregnant women (0.7–1.4 µmol/L). Only about 20% of the women had optimal values (>1.4 µmol/L). The level of serum retinol was lower in older pregnant women (p=0.008), and at higher gestational age (p=0.009). High vitamin A levels were observed in pregnant women in the central areas of Iran and the lowest values in those in the southern areas of Iran.ConclusionsThe vitamin A status was good in 2001 but should be closely monitored also in the future. About 25% of pregnant women had a vitamin A status diagnosed as insufficient or deficient (<0.7 µmol/L). The mean serum retinol decreased as the gestational age increased. The clinical significance of this finding should be further investigated, followed by a careful risk group approach to supplementation during pregnancy.

Serum Retinol Levels in Pregnant Adolescents and Their Relationship with Habitual Food Intake, Infection and Obstetric, Nutritional and Socioeconomic Variables

“…Regarding obstetric variables, there was a negative linear correlation between gestational age and serum retinol levels, which is a similar result to those found in other studies [35,36,37]. It is important to note that even if the reduction occurs with more intensity in the second and third quarter due to plasma volume expansion and increased vitamin A transfer from the mother to the fetus, special attention throughout pregnancy is necessary, particularly in the first trimester, when the major changes in the fetal development occur.…”

“…Such a high frequency of VAD differed from the findings of other studies that also investigated its occurrence in pregnant populations. In Iran, Olang et al [35] found a VAD prevalence of 24.9% among 3270 pregnant women evaluated. In China, a study carried out by Yang et al [36] that involved 1209 pregnant women showed an inadequate prevalence in only 5.3% of the sample, while in Venezuela, a study by Ortega et al [37] was the only one with a sample of pregnant adolescents showing a 10.62% prevalence of VAD.…”

The Prevalence of Vitamin A Deficiency and Associated Factors in Pregnant Women Receiving Prenatal Care at a Reference Maternity Hospital in Northeastern Brazil

“…The findings reported here are similar to those found in China, where a frequency of VAD of 5.2% was found in a group of 1209 pregnant women evaluated in 150 urban or rural areas between 2013 and 2014 [30]. Compared to the present findings, other studies conducted in developing countries using the cut-off point of <0.70 μmol/L reported much higher prevalence rates of VAD in pregnant women: 24.6% in 3270 pregnant women in Iran [31], 20% in a sample of 80 women in Egypt [32], 18.5% in 200 women in Bangladesh [33], 15.8% in 101 women in Nigeria [34], 13.8% in 738 women in Guinea-Bissau [35], and 10.6% in 160 pregnant adolescents in Venezuela [18]. However, only the sample sizes used in the studies conducted in China, Iran, and Guinea-Bissau were large enough to yield robust data.…”

“…Other studies have shown similar results, reporting vitamin A deficiency to be more common at the end of pregnancy than at the beginning [18,30,31,35,37,52]. These findings could be explained by the increase in the maternal-fetal transfer of vitamin A due to faster fetal growth towards the end of pregnancy [53].…”

“…This could be explained by the fact that repeat pregnancies reduce or deplete maternal stocks of nutrients [56]. Conversely, other studies conducted in developing countries have found no correlation between parity and serum retinol levels [31,33,57]. …”