Kids who push aside leafy greens might be lacking vitamin K and could be at increased risk for heart problems later in life, according to new research from Augusta University.

The Georgia-based study, published in the Journal of Nutrition this month, focused on 766 healthy teenagers and the relationship between their intake of vitamin K-rich foods and heart health. Over the course of a week, patients wore activity monitors and self-reported their food intake, which wasn’t dictated by the researchers. About 70 percent of the pool had six or more days of food records to analyze. In conjunction with echocardiographs, the study’s authors drew the conclusion that kids with a lower intake of vitamin K showed signs of enlargement in the left ventricles of their hearts.

Teens who consumed less vitamin K—found in leafy greens such as spinach and cabbage—were more than three times more likely to develop left ventricular hypertrophy, the study found. About 10 percent of the cohort developed left ventricular changes that are generally associated with adults who have a history of hypertension.

Though the left ventricle might be increasing in size, the study stated, affected hearts were pumping less blood. The researchers also wrote the changes in heart function weren’t affected by other factors known to increase risk of heart disease, including sex, race, body composition, physical activity and blood pressure.

Vitamin K, or phylloquinone, is important to blood clotting and healthy bone development, Augusta University explained in a release. The evidence that lack of the vitamin can lead to thicker left ventricular walls and expansion of the chamber might be new, but it’s not the only information we have about vitamin K’s impact on heart health.

According to Augusta, research has also shown a relationship between lack of vitamin K and reduced activity of vitamin K-dependent proteins like matrix Gla, which serve important functions like preventing calcium deposits in blood vessels.

In the release, authors Norman Pollock, MD, and Mary-Ellen Fain noted only a quarter of the teens studied had adequate, nutritious food intake, and none of them consumed large amounts of vitamin K.

Pollock and Fain said there needs to be further research on the topic, but their findings suggest early dietary intervention in children could reduce future cardiovascular disease risk. Pollock is also leading a novel study which is in the process of examining the impact of vitamin K supplements on obese children already showing early signs of diabetes risk.