When the researchers examined maternal vitamin D levels during the second trimester of pregnancy, they saw no difference in fetal growth patterns or pregnancy outcomes in women with lower versus higher vitamin D status. They said more women in the study had healthy levels of vitamin D during the second trimester, so that may have diminished their abilities to detect results. Still, they said this result required more research to fully understand.
“This study provides evidence that early pregnancy — and even pre-conception — nutrition is vitally important,” Beck said. “Individual women may or may not need supplements depending on their diet and lifestyle. But healthy nutrition is critical for promoting the healthy development of a fetus. This research indicates that vitamin D levels — along with iron, folate and other essential nutrients in pregnancy — should be monitored and understood by obstetricians and women early on to promote healthy birth outcomes.”
Results pointed to the potential value of taking a supplement containing vitamin D for women who are planning a pregnancy, the researchers said.
“In this study, moms with low vitamin D status were less likely to be taking a multivitamin supplement,” Beck said. “Women should consider getting their nutritional status tested by their obstetrician prior to pregnancy and discuss whether supplementation with vitamin D is needed.”
Gernand agreed and emphasized that women should follow the Dietary Guidelines for Americans.
“We can't just assume that everybody is deficient, but proper nutrition is something that needs to be on your radar if you may become pregnant," Gernand said. “And this study provides evidence that vitamin D appears to be an important part of a pregnant woman’s nutritional health.”
Muzi Na, associate professor of nutritional sciences at Penn State; Nathan Blue and Robert Silver of University of Utah Health; William Grobman of Ohio State University Wexner Medical Center; Jonathan Steller of University of California, Irvine; and Christina Scifres of Indiana University School of Medicine also contributed to this research.
The National Institutes of Health, the University of Utah and the Penn State Department of Nutritional Sciences funded this research.