New study addresses ‘important gaps’ in iron status knowledge

Iron deficiency is more prevalent in the second and third trimesters of pregnancy, whilst Mexican American and non-Hispanic black pregnant women are also at higher risk, according to a new study assessing the iron status of a representative sample of US women.

The study, published in the American Journal of Clinical Nutrition, describes the distribution of total body iron and the prevalence of iron deficiency on the basis of total body iron in US pregnant women. The study also found that that iron deficiency (as defined by total body iron of less than 0 mg per kg) is more prevalent than previously reported in non-pregnant women and children aged between one and five years old.

“To our knowledge, we present the first data on total-body iron distributions from a representative sample of US pregnant women … These data fill an important need for monitoring the iron status of pregnant women, which has been identified as a public health objective,” said the researchers, led by Dr Zuguo Mei from the Centers for Disease Control and Prevention, USA.

Commenting on the study, Harry Rice, PhD, of the United Natural Products Alliance (UNPA), told NutraIngredients-USA that the results of the study are “in line with recommendations from the Center for Disease Control and Prevention (CDC), as well as the Institute of Medicine (IOM), for supplementation to meet the iron requirements of pregnancy.”

“Of course, one should consult with her physician prior to supplementing with iron during pregnancy,” added Rice.

Iron status

Iron deficiency is the most common form of nutritional deficiency. The authors highlighted that pre-school children, and women of childbearing age are at highest risk of suffering from iron deficiency.

The authors noted that the Centers for Disease Control and Prevention (CDC), the American College of Obstetricians and Gynecologists, and the Institute of Medicine (IoM) recommend “universal consumption of prenatal supplements with iron to meet pregnancy requirements and prevent anemia.”

In addition, recent randomized controlled trials have suggested that universal supplementation with iron to meet pregnancy requirements can reduce risk of low birth weight and preterm births.

To test such findings, the National Health and Nutrition Examination Survey (NHANES) oversampled pregnant women during 1999–2006, and in 2003, NHANES started measuring sTfR and serum ferritin to asses iron status.

Study details

“We present the first estimates of total body iron, sTfR, and serum ferritin for pregnant women included in NHANES 1999–2006 …We also examined the distribution of total body iron by survey, age group, race-ethnicity, trimester, parity, education, and family income,” said the researchers.

Dr Mei and colleagues found that pregnant women in the first trimester had a higher mean total body iron than pregnant women in the second or third trimesters.

The prevalence of iron deficiency in non-Hispanic white pregnant women was found to be significantly lower than in Mexican American or non-Hispanic black pregnant women.

In addition Mei and co-workers found that iron deficiency prevalence in pregnant women “increased significantly” with each trimester.

Source: American Journal of Clinical Nutrition

Published online ahead of print, doi: 10.3945/​ajcn.110.007195

“Assessment of iron status in US pregnant women from the National Health and Nutrition Examination Survey (NHANES), 1999–2006”

Authors: Z. Mei, M.E. Cogswell, A.C. Looker, C.M. Pfeiffer, S.E Cusick, D.A Lacher, L.M. Grummer-Strawn