Giving seven times more vitamin D during pregnancy improves children’s memory at 10 years old. The problem is in the fine print

During pregnancy, the recommendations of supplementation They are an area where science advances with lead feet, since the most important thing is always to guarantee safety. One of these supplements that is heard the most is vitamin Dtraditionally known for its role in calcium absorption and bone health, but which has been in the spotlight for years for its possible impact on neurodevelopment.

A new study of Danish origin has put its objective on this statement to be able to clarify what happens when a mother supplements with vitamin D during pregnancy. Through its publication in JAMAtells how, to achieve good results, almost 500 children were analyzed for several years until finally being able to see if they had cognitive improvement during their childhood.

What were they based on? To understand this discovery we have to go back in time to a randomized clinical trial titled as COPSAC2010whose initial results were published in 2016. This trial sought to evaluate whether vitamin D prevented the risk of suffering from asthma or persistent wheezing in babies, and to verify this the researchers divided the mothers into two groups from the 24th week of gestation:

• One group would receive the standard recommended dose of vitamin D of 400 IU per day.
• The other group had a “megadose” of vitamin D of 2,800 IU daily.

The discovery. Taking advantage of this valuable group of 498 children, the research team decided to get more out of it, since when these children reached 10 years of age they were subjected to rigorous cognitive tests to see if the fact of having given vitamin D to their mother during pregnancy had left its mark on their brain. In this way, two objectives were covered with a single investigation.

Here the results revealed that children in the high supplementation group showed a modest but significant improvement in verbal and visual memory compared to the children of mothers who took the standard dose of vitamin D. Although something important to note is that it puts to rest any idea that this supplementation is a machine to “create geniuses”, because there were no differences in IQ and they only saw that the ability to retain information was improved.

The small print. Given such a finding, it is tempting to think that all pregnant women should multiply their vitamin D intake to give their children an advantage over others. But here we must pay attention to different problems, such as that the original trial was designed to measure respiratory problems and not neurological development. This means that drawing conclusions from here reduces the statistical robustness of the discovery.

But this is not the only problem, since we have seen that the effect is “modest” without seeming to give children a great advantage. And furthermore, the study is based on women who already had normal vitamin D levels before the study, so it is not clear how this dose would act in populations that truly have some type of chronic deficiency of the vitamin.

Will there be changes? At the moment, these studies do not justify the need to recommend that all pregnant women supplement their diet with vitamin D, as is the case with other supplements such as folic acid. The real value of this research is not to give us an immediate new prescription, but to open the door to future clinical trials specifically designed to unravel how what happens in the womb continues to shape our brains a decade later.

Images | amylla battani

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