Pregnant women’s vitamin D levels may impact children’s IQ, research finds

03 Nov 2020 --- Pregnant women’s vitamin D levels could be associated with their children’s IQ, suggesting that higher vitamin D levels may lead to greater childhood IQ scores.

This is according to a new study, published in The Journal of Nutrition, which also identified significantly lower levels of vitamin D levels among Black pregnant women.

“I hope our work brings greater awareness to this problem, shows the long-lasting implications of prenatal vitamin D for the child and their neurocognitive development, and highlights that there are certain groups providers to which we should be paying closer attention,” says Melissa Melough, the lead author of the study.

High risk groups recommended for screening
Wide-spread testing of vitamin D levels is not generally recommended, but health care providers should be looking out for those who are at higher risk, including black women, stresses Melough

According to the researchers, as many as 80 percent of black pregnant women in the US may be deficient in vitamin D.

“Melanin pigment protects the skin against sun damage, but by blocking UV rays, melanin also reduces vitamin D production in the skin,” Melough remarks.

“Because of this, we weren’t surprised to see high rates of vitamin D deficiency among black pregnant women in our study.”

An essential nutrient aiding in brain development
A mother’s vitamin D supply is passed to her baby in utero and helps regulate brain development processes. 

Melough notes that vitamin D is “one of the most difficult nutrients” to get in adequate amounts from our diets alone.

Melough highlights that even though many pregnant women take a prenatal vitamin, this may not correct an existing vitamin D deficiency.

Of the women participating in the study, approximately 46 percent of the mothers-to-be were deficient in vitamin D during their pregnancy.

Melough and her co-authors used data from a cohort in Tennessee called the Conditions Affecting Neurocognitive Development and Learning in Early Childhood (CANDLE) study. 

CANDLE researchers recruited pregnant women to join the study starting in 2006 and collected information over time about their children’s health and development.

After controlling for several other factors related to IQ, higher vitamin D levels in pregnancy were associated with higher IQ in children ages four to six years old. 

Although observational studies like this one cannot prove causation, Melough believes her findings have important implications and warrant further research.

The importance of supplementation
The recommended daily intake of vitamin D is 600 international units (IU). On average, Americans consume less than 200 IU in their diet.

While vitamin D deficiencies are quite prevalent, Melough notes there is a relatively easy solution to the problem. 

Foods that contain higher levels of vitamin D include fatty fish, eggs and fortified sources like cow’s milk and breakfast cereals. 

Still, Melough notes that vitamin D is one of the most difficult nutrients to get in adequate amounts from our diets alone.

“It can be difficult to get adequate vitamin D through diet, and not everyone can make up for this gap through sun exposure, so a good solution is to take a supplement,” she highlights.

Vitamin D-fortified F&B NPD has already emerged in the industry spotlight. Last July, PLT Health Solutions’ mushroom-derived Earthlight Whole Food Vitamin D gained approval of a Food Additive Petition from the US Food & Drug Administration (FDA).

Steve Fink, vice president of marketing at PLT Health Solutions previously spoke to NutritionInsight about vitamin D’s “great renaissance.”

Future research pathways to explore
Additional research is needed to determine the optimal levels of vitamin D in pregnancy, but Melough hopes this study will help to develop nutritional recommendations for pregnant women. 

“I want people to know that it’s a common problem and can affect children’s development,” Melough remarks. 

“Vitamin D deficiency can occur even if you eat a healthy diet. Sometimes it’s related to our lifestyles, skin pigmentation or other factors outside of our control.”

Melough also hopes the study will help health care providers address disparities among women of color and those who are at higher risk for vitamin D deficiency.

Edited by Benjamin Ferrer