A new study has found that adults who had low levels of vitamin D as children and teens may be at a heightened risk of heart issues.

The study, published in the Journal of Clinical Endocrinology & Metabolism, examined the relationship between low levels of vitamin D and increased thickness of the arteries, also called increased carotid intima-thickness (IMT). The researchers analyzed 2,148 volunteers and measured their vitamin D levels from ages 3 to18. An optimal vitamin D level is between 30 and 50.

Researchers then checked the study participants’ arteries at ages 30 to 45, according to a news release. Thickening of the arteries is believed to be a risk factor for developing cardiovascular disease.

“Our results showed an association between low 25-OH vitamin D levels in childhood and increased occurrence of subclinical atherosclerosis in adulthood,” study author Markus Juonala, of the University of Turku Finland, said in the news release. “The association was independent of conventional cardiovascular risk factors including cerium lipids, blood pressure, smoking, diet, physical activity, obesity indices and socioeconomic status.”

The research further found that those who had the lowest vitamin D levels in childhood had significantly higher prevalence of high-risk IMT as adults. Study authors called for more research to determine whether low vitamin D levels have a causal role in the development of artery thickness. They also noted that their findings suggested an association between low vitamin D levels and artery thickness in adulthood, not necessarily stroke and heart disease risk.