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:4/11/2017)... BROOKLYN, N.Y. , April 11, 2017 /PRNewswire-USNewswire/ ... identical fingerprints, but researchers at the New York ... University College of Engineering have found that partial ... fingerprint-based security systems used in mobile phones and ... previously thought. The vulnerability lies in ...
(Date:4/5/2017)... April 5, 2017  The Allen Institute for Cell ... Explorer: a one-of-a-kind portal and dynamic digital window into ... data, the first application of deep learning to create ... cell lines and a growing suite of powerful tools. ... these and future publicly available resources created and shared ...
(Date:4/4/2017)...   EyeLock LLC , a leader of iris-based ... Patent and Trademark Office (USPTO) has issued U.S. Patent ... an iris image with a face image acquired in ... 45 th issued patent. "The ... the multi-modal biometric capabilities that have recently come to ...
Breaking Biology News(10 mins):
(Date:10/12/2017)... ... October 12, 2017 , ... They call it ... biological network, a depiction of a system of linkages and connections so complex ... associate professor of computer science at Worcester Polytechnic Institute (WPI) and director of ...
(Date:10/12/2017)... ... October 12, 2017 , ... DuPont ... today that they have entered into a multiyear collaboration to identify and characterize ... with additional tools for gene editing across all applications. , Under the terms ...
(Date:10/12/2017)... Irvine, ca (PRWEB) , ... October 12, 2017 ... ... for the Surgical Wound Market with the addition of its newest module, US ... the $1.2B market for thrombin hemostats, absorbable hemostats, fibrin sealants, synthetic sealants and ...
(Date:10/12/2017)... CA (PRWEB) , ... October ... ... (https://www.onramp.bio/ ) has launched Rosalindâ„¢, the first-ever genomics analysis platform specifically designed ... bioinformatics complexity. Named in honor of pioneering researcher Rosalind Franklin, who made ...
Breaking Biology Technology: