Vitamin A, a nutrient found in foods like eggs, meat and dairy products, appears to play a key role in preventing heart defects in developing embryos and may promote healthy adult hearts as well, according to a UW-Madison scientist.

“Vitamin A insufficiency in expecting mothers can lead to heart problems in developing fetuses,” says Susan Smith, a nutritional scientist in the College of Agricultural and Life Sciences. “It’s important that women consider whether they are getting enough vitamin A before they plan a pregnancy.” For many women, lack of vitamin A is a real problem: a recent study of WIC recipients suggests that 22 percent receive limited amounts of the nutrient.

Heart malformations are among the most common birth defects in both humans and animals, affecting seven out of every 1,000 live human births in the United States. They can range from mild to life-threatening, and treatment may require medication or surgery. Lack of proper nutrition in mothers is known to increase the likelihood of heart defects in children, but Smith says that the specific role of vitamin A was unclear when she began her research.

Smith and her team examined how retinoids, a class of vitamin A compounds, contribute to heart development in mouse embryos. They found that when the embryos lacked the ability to transport retinoids to target cardiac tissue they were likely to develop heart problems. The fact that this relationship is apparent in mice indicates that vitamin A likely contributes to heart development in humans as well, says Smith. Furthermore, she adds that “there is the potential that not getting enough vitamin A could cause problems for an adult as well, a real issue given that cardiovascular disease is the leading cause of death in the U.S.”

Women who are planning to become pregnant should try to maintain a healthy, varied diet and consult with a doctor about using a prenatal vitamin supplement, says Smith. Although vitamin A appears to promote heart development, women should be careful not to take more than the recommended daily allowance. Too high a level of vitamin A can be dangerous to a fetus, she says.

Smith”s work is funded by a Hatch grant from the USDA, and by the state of Wisconsin.