Calcium and zinc intake before conception is associated with reduced risk of hypertensive disorders of pregnancy

People who consumed more calcium and zinc in the three months before conception were significantly less likely to suffer from hypertension during pregnancy compared with those who had low intakes of these essential minerals, according to new research.

The findings highlight the importance of focusing on nutrition before conception, not just during pregnancy, to ensure a healthy pregnancy.

“Our findings highlight the importance of preconception dietary calcium and zinc intake, which may potentially reduce the risk of hypertensive disorders during pregnancy,” says Liping Lu, MD, who conducted the study as a postdoctoral fellow at Columbia University and is now an assistant professor at Ball State University. “Higher preconception intake of zinc and calcium, from diet and supplements, is associated with a lower risk of hypertensive disorders during pregnancy.”

Lou will present these results at NUTRITION 2024, the American Society of Nutrition's premier annual meeting, which runs June 29-July 2 in Chicago.

Hypertension, or high blood pressure, is one of the most common disorders during pregnancy and can cause harm to both the pregnant woman and the developing fetus. Given the potential adverse effects of antihypertensive drugs during pregnancy, researchers have focused on the possibility of preventing dangerous hypertensive disorders such as preeclampsia through modifiable factors such as nutrition.

While many people begin to pay attention to their nutrition once they become pregnant, the researchers noted that a person's nutritional status before conception is also important, as it may take time for the body to correct deficiencies or imbalances.

“A woman’s health during the preconception period is strongly associated with pregnancy outcome. Adequate nutrient or mineral stores in the body before conception can provide optimal nutrient levels for conception and support the early stages of fetal growth and development,” says Liping Lu, MD, assistant professor at Ball State University.

The researchers conducted two separate studies using data from more than 7,700 pregnant women across the United States who provided information about their health and diet through a study called the First Pregnancy Outcomes Study: Monitoring Expectant Mothers. One study focused on calcium, and the other on zinc. The researchers analyzed the association between preconception intake of each mineral and the incidence of hypertensive disorders during pregnancy, accounting for demographic, lifestyle, and health factors that are also associated with hypertension risk.

Results showed that individuals in the highest quintile of preconception calcium intake were 24% less likely to experience hypertensive disorders during pregnancy compared to those in the lowest quintile. For zinc, participants were divided into quartiles, and those with the highest preconception zinc intake were 38% less likely to experience hypertensive disorders during pregnancy than those with the lowest zinc intake.

As with any observational study, the results do not necessarily prove cause and effect. However, the results are consistent with other studies that have linked higher intakes of the two minerals to a lower risk of hypertension outside of pregnancy. In addition, calcium and zinc are known to play important roles in metabolic processes related to maintaining healthy blood vessels, providing a plausible biological explanation for why these minerals may help prevent blood pressure disorders.

The National Academies of Sciences, Engineering, and Medicine recommend that women of childbearing age consume 1,000 milligrams of calcium and 8 milligrams of zinc daily.