FACS researcher to study the role of vitamin D in high-risk pregnancies

Vitamin D is known to be integral to bone development, and researchers believe this may especially be true during pregnancy.

A team led by Sina Gallo, an associate professor in the UGA College of Family and Consumer Sciences, seeks to learn how maternal obesity affects vitamin D metabolism during pregnancy. Currently, no pregnancy-specific vitamin D guidance exists.

The two-year project, funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development, will also explore the association between maternal vitamin D levels and bone health outcomes for their babies.

The team includes researchers from the Arkansas Children’s Nutrition Center.

“Our collaborative research team is well-positioned to do this work with complementary expertise in clinical biochemistry, micronutrient requirements, maternal and child nutrition and development, vitamin D metabolomics and biostatistics,” Gallo said. “This may lead to identification of novel clinical biomarkers for the assessment of vitamin D during pregnancy. Further, it will identify pregnancy-specific targets for current vitamin D assessment methods and critical time periods for intervention which will directly inform subsequent clinical trials among high-risk subgroups of the U.S. population.”

Here, Gallo answers a few questions about the project.

What is vitamin D?

Vitamin D is a unique fat-soluble vitamin because we can produce it when our skin is exposed to UV rays from the sun. However, sun exposure is not considered a safe or reliable source of vitamin D and as a result, most of our vitamin D intake still needs to come from dietary sources. But vitamin D is naturally found in only a limited number of foods, such as fatty fish, so many people rely on fortified foods like milk and other dairy products, or on supplements to meet their needs. Vitamin D is best known for its role in calcium absorption, making it essential for bone health.

Why is vitamin D important during pregnancy?

Adequate vitamin D intake is especially important during pregnancy because it supports both maternal health and fetal development. Because bone development begins in utero, a maternal vitamin D deficiency can negatively affect the mother’s bone health as well as the healthy skeletal development of her baby — which may have consequences later in life.

Emerging research also suggests that vitamin D may play roles beyond bone health. Lower vitamin D levels during pregnancy have been associated with an increased risk of complications such as gestational diabetes, preeclampsia and low birth weight.

Who is at risk for vitamin D deficiency?

Certain women may be at higher risk of deficiency, including those with darker skin pigmentation, living in more northern latitudes or those with limited sun exposure. Women with obesity also have a higher risk of vitamin D deficiency.

It is still unclear whether women with obesity should receive higher doses of vitamin D during pregnancy, or when supplementation should begin.

In the past, it was thought that vitamin D can get trapped in fat tissue, leaving less vitamin D available in the bloodstream among people with obesity. More recently, research suggests that obesity may also interfere with how the body activates and breaks down vitamin D in the body.

What does this project set out to accomplish?

This project aims to understand how the body uses vitamin D during pregnancy, and whether this process is affected by maternal obesity. In addition, we aim to identify vitamin D blood levels during pregnancy that are associated with better bone outcomes in infants.

We are collaborating with Aline Andres and her team at the Arkansas Children’s Nutrition Center, who have conducted multiple studies following women throughout their pregnancies, with their children tracked into later childhood. These studies aim to understand how a mother’s health and her behaviors during pregnancy influence her child’s growth and development.

In this project, we will use advanced biochemical methods to measure several markers of vitamin D utilization in about 100 microliters of blood (roughly two drops!) collected from women with and without obesity at each trimester of pregnancy. We will then examine how these markers relate to bone activity and bone density in their children at 1 and 2 years of age.

This study will help guide future research on how much vitamin D is needed in pregnancy to improve babies’ future health.