A new study published in The Journal of Nutrition provides further evidence that all women who could become pregnant, who are pregnant, or who are breastfeeding will benefit from a daily multivitamin-mineral supplement.

Iodine is essential to produce thyroid hormones, which are required for normal growth and brain development of the fetus and infant. Contributing to a limited body of literature on iodine status of mother-infant dyads, Dr. Jesse Bertinato (Health Canada) and co-authors assessed the iodine status of 132 mother-infant pairs.

The percentages of mothers that used a multivitamin-mineral supplement containing iodine were 90% in pregnancy and 79% and 59% at 1 and 6 months of lactation, respectively.  At 1 month of age, 99% of the infants were breastfed, with 70% exclusively breastfed. None of the infants <12 months of age consumed an iodine supplement. Maternal iodine status was assessed using the breastmilk iodine concentration. Iodine intakes of infants from 1–36 months of age were estimated from urinary iodine and creatinine (a measure of kidney function and urine dilution) concentrations.

Breastmilk iodine concentrations in the first month of lactation indicated adequate maternal iodine status but these concentrations declined substantially by the sixth month of lactation. The decline in maternal iodine status coincided with declining supplement use. Iodine status of infants were adequate throughout infancy, indicating sufficient iodine intakes from breastmilk during the first few months of breastfeeding. In older infants, appropriate complementary feeding practices helped meet iodine requirements. Because most pregnant and lactating women do not meet iodine requirements, these results reinforce recommendations that all pregnant and lactating women in North America take a multivitamin-mineral supplement containing iodine.

References

Jesse Bertinato, Jeremiah Gaudet, Nimal De Silva, Smitarani Mohanty, Cunye Qiao, Matthew Herod, Nathalie Gharibeh, Hope Weiler, Iodine Status of Mother-Infant Dyads from Montréal, Canada: Secondary Analyses of a Vitamin D Supplementation Trial in Breastfed Infants, The Journal of Nutrition, Volume 152, Issue 6, June 2022, Pages 1459–1466, https://doi.org/10.1093/jn/nxac047.

Images via canva.com.

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Kathy Beerman, PhD

Dr. Kathy Beerman teaches in the School of Biological Sciences at Washington State University. The author of several published articles, she is interested in research that focuses on the efficacy of a novel approach to treating iron deficiency anemia in rural regions of Guatemala and Ecuador. Dr. Beerman teaches an undergraduate nutrition course for health majors, as well as a course that prepares students to participate in a 10-day medical mission to Guatemala. Since joining the faculty at Washington State University in 1990, she has been the recipient of several teaching awards (the Burlington Northern Faculty Meritorious Achievement in Teaching Award, the R.M. Wade Foundation Award for Excellence in Teaching, and the Sahlin Faculty Excellence Award for Instruction). More recently, she received the CAS Outstanding Achievement Award in International Activities (2017) and the President’s Award for Leadership (2018). Other scholarly activities include co-author of two introductory nutrition textbooks (Nutritional Sciences: From Fundamentals to Food and NUTR).