Vitamin a Intake of Middle- and Upper-Income Pregnant Women

Abstract

While vitamin A is vital for fetal organ development, recent research has reaffirmed the teratogenicity of excessive doses of preformed vitamin A. This study evaluates the adequacy of vitamin A intake from food sources and ascertains whether excess retinol intake from food plus supplements is a concern in middle- and upper-income women during their first trimester of pregnancy. Ninety-four healthy women were enrolled during the initial prenatal visit to a local obstetrician. A 24-hour dietary recall was obtained. Forty-four women (47%) took retinol-containing supplements during this 24-hour period; only eight of the supplements were prescription prenatals. Subjects were separated into two categories: retinol supplement users (n=44) and non-users (n=50). Food records were analyzed using nutrient analysis software. Supplement information was obtained from manufacturers. Retinol intake data were analyzed using the contingency table method to compare two binomial proportions and the unpaired t-test was used to compare energy intakes between groups. Energy intakes were not significantly different between the two groups. Subjects in each group were equally likely to consume less than the RDA (800 RE) of vitamin A from food sources. Vitamin A intake was less than the RDA in 44% of the subjects. Supplement users were more likely to consume excess retinol (defined as two times the RDA in retinol, >1600 RE) from food and supplements combined (36% vs. 0% in supplement user and non-user groups, respectively, p<0.001). These data indicate that although vitamin A intake may be inadequate in greater than one third of middle- and upper-income women during the first trimester of pregnancy, indiscriminate use of retinol-containing supplements may provide excess retinol when consumed with a normal diet. Assessing the adequacy of each woman's diet and providing diet counseling on healthy eating during pregnancy may enhance vitamin A intake. If supplementation is necessary, vitamin A provided as B-carotene would eliminate the possibility of excess retinol from dietary supplements.