The team from Purdue University says most pregnant and lactating women use dietary supplements, which contribute many nutrients in doses above the Recommended Dietary Allowance (RDAs).
“Although inadequate Intakes of folate and iron are of concern among pregnant women who are not using supplements, supplement users often consumed high doses,” the study thinks.
“This suggests a potential need of health care providers to discuss dietary supplement use and the recommended doses of nutrients during pregnancy and lactation.
Nutrient requirements increase during pregnancy and lactation, especially for certain micronutrients such as folate, iron, iodine, and copper.
To prevent possible nutrient inadequacies, clinicians and dietitians routinely recommend or prescribe prenatal supplements.
Many European countries recommend pregnant women and those about to become pregnant eat folate-rich foods and take folic acid supplements (400 micrograms per day (μg/day)).
The European Food Safety Authority (EFSA) also advises pregnant and breastfeeding women to consume 100-200 milligrams (mg) of a Docosahexaenoic acid (DHA) supplement per day as well as 1-2 servings of fatty fish) per week as recommended for the general population.
However a recent report concludes over 10% of pregnant women are not consuming enough vitamins A, B6, C, D, and E, folate, calcium, iron, magnesium, and zinc even though 70% reported the use of dietary supplements.
Study details
Along with colleagues from the Universities of Utah and Colorado, the team began looking into cross-sectional data from 1,314 pregnant, 297 lactating, and 8,096 nonpregnant and nonlactating women (aged 20–44 years) in the United States.
Data about dietary supplement use in the past 30 days was collected as was information on prevalence of nutrient-specific supplement use and mean daily nutrient intakes from supplements among users.
Other information collected included motivations for supplement use. Differences by age, income, and trimester within pregnant women were also considered.
Results revealed that 77% of pregnant women and 70% of lactating women used one or more dietary supplements, whereas 45% of nonpregnant and nonlactating women used supplements.
Specifically, 64% of pregnant and 54% of lactating women used prenatal supplements.
Mean intakes of thiamin, riboflavin, niacin, folic acid, vitamins B6, B12, and C, iron, and zinc from supplements alone were at or above their respective recommended dietary allowances (RDAs) among pregnant and lactating supplement users.
About half of pregnant and 40% of lactating women took supplements based on the recommendation of a health care provider.
Among pregnant women, those in their first trimester, aged 20–34 years, or in a lower-income family were less likely to use supplements compared with their counterparts.
High doses may be appropriate
“The majority of pregnant and lactating women took at least one dietary supplement at some time during their pregnancy, which contributed many nutrients (eg, thiamin; riboflavin; niacin; folic acid; vitamins B6, B12, and C; iron; and zinc) in doses above the RDAs among users,” the authors say.
“Although folic acid and iron supplementation is recommended during pregnancy, some supplement users may consume high doses that lead to excessive intakes.
The team also say that some of these high doses may be appropriate when recommended by health care providers owing to special medical conditions.
“The use of supplements containing iodine, magnesium, and choline was relatively low among all women of reproductive age, regardless of pregnancy or lactation status,” the study continues.
“Less than half pregnant and lactating women were taking at least one supplement based on a health care provider's recommendation. Health care professionals should be aware of and communicate information about nutrition and dietary supplement use, especially for folic acid and iron.”
Source: Obstetrics & Gynecology
Published online ahead of print: doi: 10.1097/AOG.0000000000003657
“Dietary Supplement Use and Its Micronutrient Contribution During Pregnancy and Lactation in the United States.”
Authors: Jun, Shinyoung et al.