Navigation Links
Study associates excess maternal iodine supplementation with congenital hypothyroidism in newborns
Date:7/26/2012

Cincinnati, OH. July 26, 2012 Congenital hypothyroidism is thyroid hormone deficiency at birth that, if left untreated, can lead to neurocognitive impairments in infants and children. Although the World Health Organization recommends 200-300 g of iodine daily during pregnancy for normal fetal thyroid hormone production and neurocognitive development, the US Institute of Medicine considers 1,100 g to be the safe upper limit for daily ingestion. A case series scheduled for publication in The Journal of Pediatrics describes three infants who developed congenital hypothyroidism as a result of excess maternal iodine supplementation.

Kara Connelly, MD, and colleagues from Oregon Health & Science University, Doernbecher Children's Hospital, Boston University School of Medicine, State of Oregon Public Health Laboratory, and Randall Children's Hospital at Legacy Emanuel describe three infants with congenital hypothyroidism whose mothers had taken 12.5 mg of iodine daily, 11 times more than the safe upper limit, while pregnant and/or breastfeeding. Iodine is transferred from the mother to the infant through the placenta or breast milk. The three infants had blood iodine levels 10 times higher than healthy control infants (measured from newborn screening filter paper).

Excess iodine causes the thyroid to temporarily decrease function to protect against hyperthyroidism (Wolff-Chaikoff effect). Adults and older children are able to "escape" from this effect after several days of excess iodine to avoid hypothyroidism. However, the immature thyroid glands of fetuses and newborns have not developed this protective effect and are more susceptible to iodine-induced hypothyroidism. Although infants recover normal thyroid function after acute iodine exposure (e.g., a few days of topical iodine application), continuous excessive iodine exposure to the fetal and neonatal thyroid gland may cause long-term harmful effects on thyroid function.

Sources of iodine include nutritional supplements, prenatal vitamins, and seaweed (kelp). According to Dr. Connelly, "The use of iodine-containing supplements in pregnancy and while breastfeeding is recommended in the United States. However, these cases demonstrate the potential hazard of exceeding the safe upper limit for daily ingestion." Excess iodine ingestion from supplementation is often unrecognized because it is not routine practice to ask mothers of infants with congenital hypothyroidism about nutritional supplements taken during pregnancy. Pregnant or breastfeeding women should discuss the safe dosages of nutritional supplements with their doctors prior to including them in their daily regimen.


'/>"/>
Contact: Monica Helton
journal.pediatrics@cchmc.org
513-636-7140
Elsevier
Source:Eurekalert

Related biology news :

1. New study associates excess maternal iodine supplementation with congenital hypothyroidism
2. Its a bird, not a plane: York U study finds migrating songbirds depart on time
3. Alpine Fault study shows new evidence for regular magnitude 8 earthquakes
4. Researchers study knee stress at tissue, cellular levels
5. DataONE answers the call for new tools to study the Earth in this era of Big Data science
6. Study shows economic feasibility for capturing carbon dioxide directly from the air
7. New study: Raisins as effective as sports chews for fueling workouts
8. PSU study finds caffeinated coastal waters
9. New study announced that will use genetics to test for Alzheimers risk
10. Study points to causes of high dolphin deaths in Gulf of Mexico
11. Study examines autism law, financial burdens
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/18/2016)... March 18, 2016 --> ... Biometrics, ICT, Manned & Unmanned Vehicles, Physical infrastructure and Perimeter ... companies in the border security market and the continuing migration ... Europe has led visiongain to publish ... success. --> defence & security companies in ...
(Date:3/14/2016)... http://www.apimages.com ) - ... - Renvoi : image disponible via AP Images ( ... --> DERMALOG, le leader de l,innovation ... d,empreintes digitales pour l,enregistrement des réfugiés en Allemagne. ... produire des cartes d,identité aux réfugiés. DERMALOG dévoilera ...
(Date:3/9/2016)... This BCC Research report provides an overview ... Sequencing (RNA Seq) market for the years 2015, 2016 ... reagents, data analysis, and services. Use this ... market such as RNA-Sequencing tools and reagents, RNA-Sequencing data ... each segment and forecast their market growth, future trends ...
Breaking Biology News(10 mins):
(Date:5/25/2016)... ... May 25, 2016 , ... ... variety of fracture-specific plating options designed to address fractures of the distal tibia ... solutions. , The Acumed Ankle Plating System 3 is composed of seven plate ...
(Date:5/25/2016)... ... ... Lady had been battling arthritis since the age of two and at ... owner Hannah sought the help of Dr Jeff Christiansen of Superior Veterinary Surgical ... and help with the pain of Lady’s arthritis. Dr Christiansen suggested that in conjunction ...
(Date:5/24/2016)... ... May 24, 2016 , ... ... re-branded identity. The new Media Cybernetics corporate branding reflects a results-driven revitalization for ... and image analysis. The re-branding components include a crisp, refreshed logo and a ...
(Date:5/23/2016)... , May 23, 2016 - Leading CRO,s ... - Frontage Implement a Single Platform to Manage End-to-end ... Traceability Within the Bioanalytical lab Frontage Laboratories, a full-service ... States and China , has selected ... facilities. In addition to serving as the global electronic lab notebook ...
Breaking Biology Technology: