Should i take iodine supplements during pregnancy? Negative, responds the independent medical journal Prescribe, who publishes an article on iodine intakes during pregnancy in its March 2021 issue.

Sold in pharmacies or on the internet, these iodine supplements often associated with other elements (vitamin B9, copper, zinc, magnesium, vitamin D …) in a formula “pregnancy multivitamins “ would therefore be more dangerous than beneficial.

“Slight” deficiencies in France

Why such a conclusion? The intake of iodine depends mainly on the diet and the proximity of a coastline. In Europe, it is true that iodine intake through food is sometimes insufficient. But according to the data collected by theWorld Health Organization (WHO) between 2002 and 2017, “Europe is globally a zone of “moderate” iodine deficiency“recalls the review Prescribe.

Better, France as Belgium are areas of “slight” deficiency, according to the results of ioduria, that is to say of the presence of iodine in the urine, of their inhabitants.
And, in 2020, the Global Iodine Network report (IGN) considered iodine intakes as “adequate“among adults in France.

No proven scientific interest

According to two meta-analyzes, the first published in 2017 in the Cochrane database, and the second in 2020 in theAmerican Journal of Clinical Nutrition, there is no good quality data demonstrating the benefit of iodine supplementation during pregnancy in countries where deficiencies are mild to moderate, such as France.

Especially since “the difference between recommended intake (200 micrograms per day for pregnant and breastfeeding women, 150 micrograms for adolescents and adults, editor’s note) and dangerous intake is not very large“warns Prescribe.

Goiter, deafness, developmental disorders …

But what are the risks associated with a said intake “dangerous“? The iodine absorbed by the mother crosses the placenta. Gold”excessive iodine intake during pregnancy exposes the unborn child to hypothyroidismThe consequences in children are hypothyroidism, goiters but also intellectual development disorders and deafness.

Thus, in 2017, the National Food Safety Agency (Handles) reported cases of fetal hypothyroidism in babies born to women who had used drugs during pregnancy “food supplements, providing them respectively 120 and 150 micrograms of iodine per day, sometimes in combination with other sources of iodine“.

Focus on a balanced diet

Problem, both iodine deficiency and excess expose the fetus to hypothyroidism. What strategy to adopt then? “When a pregnant woman is considering taking an iodized food supplement, it is prudent to check with her that her various iodine intakes (food, food supplements, drugs) are not excessive, which would be dangerous for the unborn child.” offers Prescribe.

To ensure adequate intake from the diet, consume iodized table salt, seafood including seaweed and fish, eggs and dairy products. As a general rule, a balanced diet that includes several of these foods “provides enough iodine on a daily basis“reassures the review.

Finally, she issues a final warning: beware of “multivitamin” food supplements intended for pregnant women, particularly those sold on the internet, which “sometimes contain up to 50 times more iodine than the recommended daily allowance“.