Low vitamin D at birth increases risk of high blood pressure, study says

Vitamin D deficiency from birth and early childhood may result in an increased risk of high blood pressure in late childhood and adolescence, according to new research published in the journal Hypertension.  

Researchers followed 775 children from birth to age 18 at the Boston Medical Center in Massachusetts. Most lived in a low-income, urban area and 68 percent of the children were African American. Low vitamin D levels were defined as less than 11 nanograms per millimeter (ng/ml) in cord blood at birth and less than 25 ng/ml in a child's blood during early childhood.

Compared to children who were born with adequate vitamin D levels, children born with low levels of vitamin D had an approximately 60 percent higher risk of elevated systolic blood pressure between ages 6 and 18 years old. In addition, children who had persistently low levels of vitamin D through early childhood had double the risk of elevated systolic blood pressure between ages 3 and 18 years old.

Currently, there are no recommendations from the American Academy of Pediatrics to screen all pregnant women and young children for vitamin D levels, according to Guoying Wang, MD, PhD, the study’s lead author and an assistant scientist at Johns Hopkins University Bloomberg School of Public Health in Baltimore, Maryland.

What constitutes optimal circulating vitamin D levels during pregnancy and early childhood remains an active research question, and the study results need to be replicated in other large populations, Wang said.

Vitamin D is needed for the body to absorb calcium for strong bones. It is made by our bodies when we are exposed to sunlight and found in a few foods, such as eggs, salmon, and fortified milk products. It is also available as a vitamin supplement.

High blood pressure is a leading, preventable cause of cardiovascular disease worldwide. Along with an increase in obesity among children, the prevalence of high blood pressure in children has been on the rise in recent years, especially among African American children. High blood pressure in childhood is an important risk factor for having high blood pressure and developing cardiovascular disease in adulthood.

“Our findings,” Wang said, “raise the possibility that screening and treatment of vitamin D deficiency with supplementation during pregnancy and early childhood might be an effective approach to reduce high blood pressure later in life.”