(CN) – Women trying to get pregnant again after a miscarriage should make sure to get enough vitamin D, a new study published in The Lancet recommends.
After tracking about 1,200 women aged 18 to 40 from 2007 to 2011, the researchers found that women who had sufficient levels of vitamin D were more likely to become pregnant and have a live birth as compared with women whose levels of the vitamin were insufficient. Insufficient levels of vitamin D is defined in the study as below 30 nanograms per milliliter.
The test subjects, all of whom had experienced one to two pregnancy losses previously, were tested at four clinical sites across the United States. In addition to testing the women’s serum 25-hydroxyvitamin D levels before conception, the researchers followed up with them for up to six menstrual cycles as they tried to get pregnant.
Those who conceived were tested throughout their pregnancy, and their serum 25-hydroxyvitamin D was taken at eight weeks of gestation.
Pregnancy was 10 percent more likely for women who had sufficient preconception vitamin D concentrations, the study found. And this group was also 15 percent more likely than those with insufficient levels to have a live birth.
“Among women who became pregnant, each 10 nanogram per milliliter increase in preconception vitamin D was associated with a 12-percent lower risk of pregnancy loss,” a report on the study from the National Institutes of Health states. “Vitamin D levels in the eighth week of pregnancy were not linked to pregnancy loss.”
The NIH notes that the double-blind, placebo-controlled study began as part of the Effects of Aspirin in Gestation and Reproduction (EAGeR) trial that studied whether a low-dose of aspirin every day could prevent miscarriage in women with a history of pregnancy loss.
Low-dose aspirin is defined 81 milligrams.
Of women undergoing in vitro fertilization, the researchers emphasized, few studies have linked higher levels of vitamin D to higher pregnancy rates.
“However, little research has been done on pregnancy rates and pregnancy loss in women attempting to conceive without assisted reproductive technologies,” the NIH release notes.
The researchers said more studies must be undertaken to determine whether providing vitamin D to women at risk for pregnancy loss could increase their chances for pregnancy and live birth.
Published Wednesday in The Lancet Diabetes & Endocrinology, the study was funded by the National Institutes of Health and the Doris Duke Charitable Foundation.
Sunni Mumford, in the Epidemiology Branch of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), was the study’s principal investigator.