Preterm birth—delivering before 37 weeks—is estimated to affect 12% of pregnancies in the US, and may lead to complications or be life threatening. While some causes of preterm birth are not preventable, research has discovered a possible factor that is—low maternal vitamin D status. The study was published in PLoS One and included 1,064 pregnant women, ages 18 to 45. At their first prenatal visit, all the women had their blood vitamin D levels checked. They were also offered free vitamin D supplements (5,000 IU per capsule) and given dosing recommendations based on their blood vitamin D level, the goal being 40 ng/mL or higher. Providers recommended follow-up vitamin D tests at 24–28 weeks and before delivery. After examining the women’s test results, researchers discovered that:
The overall preterm birth rate was 13% among the women who participated in the study and gave birth to a live, single baby.
Risk of preterm birth was 62% lower in women with vitamin D levels of 40 ng/mL or higher, compared with women whose vitamin D levels were 20 ng/mL or below.
In women whose vitamin D levels were below 40 ng/mL at the beginning of pregnancy, those whose levels rose to 40 ng/mL or higher during pregnancy had a 60% lower risk of preterm birth than women whose levels stayed below that goal.
The association between lower preterm birth risk and better vitamin D status was seen across all sub-categories in the study group, regardless of race or ethnicity, prior preterm birth status, or socioeconomic status.
These findings suggest that if you’re pregnant, you’ll want to ensure your vitamin D status is healthy. Sunlight exposure, which stimulates the body to make vitamin D, may be helpful. You can also get vitamin D from certain foods, like fatty fish, eggs, and fortified foods like cereal and milk, and supplements. Talk with your healthcare practitioner if you have questions about your vitamin D status, so they can help you determine if you need more vitamin D for a healthy pregnancy.
Source: PLoS One