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

Abstract

Globally, vitamin A deficiency (VAD) affects about 19.1 million pregnant women. Its occurrence is classically associated with inadequate food intake and may also be associated with socioeconomic factors and the presence of infection. The aim of this study was to determine the factors related to serum retinol levels among pregnant teenagers. The sample consisted of 89 pregnant adolescents, from whom socioeconomic, obstetric, anthropometric, and food consumption data were collected. Serum concentrations of retinol and the supposed presence of infection were determined by high-performance liquid chromatography and C-reactive protein quantification, respectively. The serum retinol concentrations were classified according to the criteria of the World Health Organization. We adopted a 5% significance level for all statistical tests. Serum retinol levels were significantly and positively associated with sanitation (p = 0.008) and pre-gestational nutritional status (p = 0.002), and negatively with the trimester (p = 0.001). The appropriate sanitation conditions and pre-pregnancy body mass index (BMI) were shown to have a protective effect against VAD. Conversely, serum retinol levels were reduced with trimester progression, favoring VAD occurrence.

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

“…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].…”

“…Consequently, the prevalence of VAD in the group of women with more than 12 years of schooling was lower. Conversely, in other studies such as that conducted to evaluate VAD in pregnant adolescents in Piauí [37] and another carried out to assess mothers in the state of Pernambuco [41], no statistically significant association was found between VAD and schooling. A fact that needs to be taken into account refers to the rapid nutritional transition occurring in Brazil that differentiates this country from others.…”

“…Issues regarding sample selection and size may also apply to the study conducted with 89 pregnant adolescents conducted in the Brazilian state of Piauí, where VAD was found in 34.8% of the women, consequently constituting a severe public health problem [37]. This very high frequency of VAD compared to the findings of the present study should be examined in the light of the large differences in sample size and the fact that the aforementioned study included only adolescents.…”

“…compound and heterogenous markers that could have increased the prevalence of the problem, although these increases were actually the result of distortion effects or biases [16,17,36,37]. …”

Status of Vitamin A and Related Compounds and Clinical Outcomes in Maternal-Infant Pairs in the Midwestern United States

“…A study conducted in Brazil investigated the relationship between serum retinol concentrations with dietary intake, socioeconomic status, obstetrics factors, nutrition status, and presence of infection in pregnant adolescents found VAD (retinol <0.70 μmol/L) in 34.8% of women. The mean ± SD retinol concentration was 0.92 ± 0.42 μmol/L, indicating the existence of a serious public health problem in this young population [21]. A second Brazilian study, conducted at a public maternity hospital in Recife, examined the serum retinol concentrations of 65 consecutive mother-newborn pairs at delivery from January to August 2008.…”