Mothers-to-be looking to give their babies the best start possible will want to be sure their bodies are providing enough vitamin D. Higher levels of vitamin D during pregnancy may lead to increased IQ scores in children, a new study suggests. The finding could give mothers-to-be, particularly women of color, a straightforward and fairly easy way to provide their babies with a stronger foundation for school.
Vitamin D deficiency is fairly common. Vitamin D does not naturally occur in many foods, so it is added to foods like milk and breakfast cereals. Our bodies are able to make vitamin D when our skin is exposed to sunlight, and it is available as a dietary supplement.
Most Americans get less than 200 international units (IU) of vitamin D from food each day. The recommended daily intake is 600 IU.
Skin color can affect the body’s ability to make and use vitamin D, researchers found when they looked at the vitamin D levels of pregnant women. The high levels of melanin pigment in people with darker skin does protect their skin from sun damage, but it also reduces the body’s ability to make vitamin D. As a result, Black women are at higher risk for vitamin D deficiencies.
Researchers noted lower levels of vitamin D among Black pregnant women. Even though most pregnant women take a prenatal vitamin, it may not be enough to correct an existing deficiency, according to Melissa Melough, lead author of the study .
Higher levels of vitamin D during pregnancy were associated with higher IQ scores in four- to six-year old children. Although the study was observational and did not prove vitamin D deficiency in pregnant women caused children to have higher IQs or otherwise, it does raise questions that warrant further investigation.
“Vitamin D deficiency is quite prevalent,” Melough said in a statement. “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.”
Melough, a nutritional epidemiologist and registered dietitian currently working at the Seattle Children's Research Institute, believes up to 80 percent of pregnant Black women in the U.S. may be deficient in vitamin D. Among the women in the study, 46 percent were vitamin D deficient while pregnant. Black women were more likely to have lower levels than White women.
The best food sources of vitamin D are fatty fish, eggs and fortified foods like milk and breakfast cereals.
Screening pregnant women for vitamin D deficiency and providing supplements, if needed, may improve brain development during infancy. Melough hopes the study will help to guide the development of nutritional recommendations for pregnant women, especially Black women and others at high risk for vitamin D deficiency.
The study is published in The Journal of Nutrition.