The Content of Selected Vitamins and Minerals During Pregnancy May be Associated With a Lower Risk of Blood Pressure Problems in Middle Age

Women who had higher levels of essential minerals in their blood during pregnancy, particularly copper and manganese, as well as vitamin B12, had a lower risk of developing high blood pressure in middle age, about 20 years later. This is according to a study presented at the American Heart Association’s Scientific Sessions 2025 in Epidemiology and Prevention | Lifestyle and Cardiometabolic Health. According to the study authors, it is the first to examine the association between pregnancy metal levels and midlife women’s blood pressure and hypertension risk.

How Certain Metals and Trace Elements Affect Blood Pressure

Manganese, selenium, magnesium and copper are among the essential trace elements that are important for a healthy body, as their antioxidant and anti-inflammatory properties can help protect against cardiovascular diseases. Previous research has shown that higher levels of manganese are associated with a lower risk of preeclampsia (high blood pressure during pregnancy). However, it is not known whether higher levels of essential metals during pregnancy can affect the risk of developing high blood pressure later in life. Furthermore, chronic exposure to the nonessential metals lead, cadmium and arsenic is associated with an increased risk of cardiovascular disease, according to the association’s 2023 scientific statement, “Contaminant Metals as Cardiovascular Risk Factors.”

“People are constantly exposed to heavy metals and trace elements, and numerous studies have shown that exposure to these metals and elements can affect cardiovascular health, particularly high blood pressure,” said lead study author Mingyu Zhang, Ph.D., M.H.S., an epidemiologist and lecturer in medicine at Beth Israel Deaconess Medical Center and Harvard Medical School, both in Boston. In their study, the researchers wanted to examine how the levels of essential metals and elements during pregnancy can affect blood pressure and the risk of high blood pressure in middle age. The researchers analyzed data from Project Viva, an ongoing longitudinal study that began in 1999 and examines women and their children in eastern Massachusetts. Nearly 500 women participated in the study during early pregnancy between 1999 and 2002. Researchers measured the concentrations of nonessential metals (arsenic, barium, cadmium, cesium, mercury, and lead), essential minerals (copper, magnesium, manganese, selenium, and zinc), folate acid, and vitamin B12 in blood samples taken during study enrollment. After almost 20 years of follow-up, the researchers conducted a midlife visit between 2017 and 2021 with the same study participants, who now had an average age of 51.2 years. The researchers measured blood pressure to determine possible associations between individual metals and blood pressure as well as the risk of hypertension. Participants were classified as hypertensive if their blood pressure readings were above 130/80 mm Hg or if they reported taking antihypertensive medication. In addition, the potential collective effects of all 11 metals and two micronutrients on blood pressure were analyzed.

What the Study Found

• After the researchers took sociodemographic factors into account, doubling blood levels of copper and manganese during pregnancy was associated with a 25% and 20% lower risk of high blood pressure in midlife, respectively.
• Because vitamin B12 levels in the blood doubled during pregnancy, women had an average systolic blood pressure 3.64 mm Hg lower and a diastolic blood pressure 2.52 mm Hg lower almost two decades later. About 95% of the study participants had vitamin B12 levels in the normal range, according to the researchers.
• Blood levels of the mixture of copper, manganese, selenium and zinc were also associated with lower blood pressure, with this association increasing with dose. Non-essential metals had no significant effect on blood pressure.

“The circulating concentrations of these metals and minerals in the blood were measured, but the sources of exposure, such as foods or dietary supplements, were not quantified, so these results should not be interpreted as recommendations,” Zhang said. Optimizing these essential metals, minerals, and vitamins, particularly copper, manganese, and vitamin B12, during pregnancy may protect against hypertension in midlife, a particularly critical period for future cardiovascular risk in women in later life.

Further research, including clinical trials, is needed to determine the optimal dietary intake of these minerals and micronutrients. The researchers hope to ultimately identify women at high risk of developing hypertension later in life and intervene during pregnancy, either through improved nutrition or supplementation.

Limitations of the study include that it was an observational study, meaning that other confounding factors not measured in the study may have influenced the results; the researchers only included a subset of the original Project Viva participants; and there were demographic differences between the included and excluded participants. In addition, the researchers did not have measurements of metal levels between delivery and midlife; and the participants were mostly white women living in eastern Massachusetts, which may limit the generalizability of the study’s findings.