A Pilot Evaluation of the Adequacy of Prenatal Vitamins to Cover Dietary Deficits During Pregnancy and Lactation.

Abstract

Objectives: The objectives of this pilot survey were (1) to compare dietary intakes during three survey windows (25-28 weeks gestation, 28-32 weeks gestation and ≥ 3 months postpartum) with the National Institutes of Health, Office of Dietary Supplements' (NIH:ODS) established recommendations for pregnant and lactating women, and (2) to evaluate the general adequacy of commonly used prenatal vitamins (PVs) to cover the identified deficits in dietary intake.

Methods: In this longitudinal pilot survey, 39 healthy consented women, aged 18-50 years with singleton pregnancies and pre-pregnancy BMI < 30.0 kg/m² were included. Items from self-reported dietary intakes during three survey windows were converted to nutritional content using Fooducate (LLC), a public database. Three-day mean intakes per survey window per subject were compared with NIH:ODS recommendations to determine dietary deficits. Eight commonly utilised PVs (identified via web searches of common prenatal vitamins and their availability in local stores) were evaluated for adequacy in correcting each dietary deficit.

Results: Nutrients that were ≥ 30% higher than the recommended RDA/AI were carbohydrates, sodium, vitamin A, and vitamin C in the first survey window; carbohydrates, sodium, and vitamin A in the second survey window; and sodium and iron in the third survey window. Nutrients that were ≥ 30% lower than the RDA/AI were potassium, vitamin D, and iron in the first survey window; potassium, vitamin D, and iron during the second survey window; and dietary fibre, potassium, vitamin C, and vitamin D in the third survey window. None of the evaluated PVs corrected all deficits, but two were close to the goal and only one corrected all vitamin D deficits.

Conclusion: Women who are or are planning to become pregnant should be educated on dietary recommendations during pregnancy and lactation, ideally such that supplements become unnecessary. However, it remains good practice to carefully consider prenatal vitamin content before selection.