SEATTLE, Wash. — For expecting mothers, vitamin D is important for their health and their baby’s too. A study finds this critical nutrient isn’t just vital for growth but also impacts a child’s intelligence as well. Researchers from Seattle Children’s Research Institute say mothers with higher vitamin D levels during pregnancy tend to have children with greater IQ scores.

Melissa Melough, the study’s lead author, adds that this connection specifically shows up in the children of Black women. The study finds vitamin D deficiency is a common problem among pregnant women, but Black mothers-to-be are at higher risk.

“Melanin pigment protects the skin against sun damage, but by blocking UV rays, melanin also reduces vitamin D production in the skin. Because of this, we weren’t surprised to see high rates of vitamin D deficiency among Black pregnant women in our study. Even though many pregnant women take a prenatal vitamin, this may not correct an existing vitamin D deficiency,” the research scientist in the Center of Child Health, Behavior, and Development says in a media release.

“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 should be paying closer attention to. Wide-spread testing of vitamin D levels is not generally recommended, but I think health care providers should be looking out for those who are at higher risk, including Black women.”

Growing list of benefits

Before discovering this link to future intelligence, previous studies have shown getting enough of this nutrient has several benefits. One study revealed a vitamin D deficiency during the developmental process leads to stunted growth and higher risk for obesity.

In the new study, researchers examined parent-child data from the Conditions Affecting Neurocognitive Development and Learning in Early Childhood (CANDLE) study. The report studied pregnant women starting in 2006 and followed them and their kids over the next few years.

After controlling for several factors which influence IQ, Melough’s team discovered that higher vitamin D levels during pregnancy had a connection to higher IQ in children between four and six years-old. Researchers caution that the findings point to a link between prenatal nutrition and intelligence, but don’t provide a cause.

“Vitamin D deficiency is quite prevalent,” Melough explains. “The good news is there is a relatively easy solution. 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.”

What’s the best way to raise your vitamin D levels?

The study finds humans need 600 international units (IU) of vitamin D each day. The average American only consumes about 200 IU through their diet. While Melough says this gap can be made up through sun exposure or supplements, not everyone will meet this goal. Foods that can increase your nutrient levels include fatty fish, eggs, cow’s milk, and breakfast cereals.

Researchers note that as many as 80 percent of pregnant Black women may have a vitamin D deficiency. Nearly half (46%) of the expecting mothers in the study were lacking the recommended amount of vitamin D. Those levels were lower among Black women when compared to White women.

“I want people to know that it’s a common problem and can affect children’s development,” the lead author concludes. “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.”

The study appears in The Journal of Nutrition.

About Chris Melore

Chris Melore has been a writer, researcher, editor, and producer in the New York-area since 2006. He won a local Emmy award for his work in sports television in 2011.

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