Could excessive iron supplements in pregnancy increase risk of type-1 diabetes?

A doubling of iron content of the infants’ blood was linked to more than twice the risk of developing childhood T1D, discovered the research team led by Herlev University Hospital, Denmark.

The scientists also found that neonates’ blood iron content increased with maternal age and that baby girls had significantly higher levels of blood iron than boys.

“To our knowledge, this is the first study to investigate and demonstrate a positive association between neonatal iron content in blood and the risk of developing T1D before the age of 16 years. Furthermore, iron content was significantly lower in boys than in girls, and increased with maternal age,” ​wrote lead author Julie Nyholm Kyvsgaard.

“This association became even stronger after adjusting for possible confounders (sex, maternal age at delivery, birth weight, gestational age, and human leukocyte antigen (HLA) risk),”​ she added.

Significance​

Iron deficiency and anaemia are common in pregnancy. Iron supplementation is frequently recommended to satisfy increased maternal demands during the term. However, a previous study​ had shown that 37% of Danish pregnant women consumed more than the recommended level of 50-70 milligrams/day (mg/d). The findings raise a concern that iron overload may possibly be involved with pancreatic beta-cell injury, although mechanisms for this are not established.

The study was of case-control design and involved 199 children diagnosed with T1D prior to age 16.    Iron was measured in the infants using a single dried blood spot sample.

Due to the observational nature of the study, no causality can be inferred.

The researchers also emphasised that other questions needed to be answered before any change to guidelines on iron supplementation could be considered.

 “Further research is obviously needed to prove causality,” ​wrote the researchers.

“Further, causes of high neonatal iron such as genetic profile and correlation with maternal iron status needs further exploration before any change in guidelines should be made,”​ they added.

Source:    Nutrients​

Volume 9, issue 11, article 1221.      DOI:   10.3390/nu9111221​​

“High Neonatal Blood Iron Content Is Associated with the Risk of Childhood Type 1 Diabetes Mellitus”​

Authors:   Julie Nyholm Kyvsgaard, Jannet Svensson, et al​

 ​