THURSDAY, May 13, 2010 (HealthDay News) -- Seventy percent of pregnant women in the United States don't get enough vitamin D, new research reveals.
What's more, the regimen of prenatal vitamins that many women take do not always provide enough vitamin D to boost levels when needed, researchers from the University of Colorado Denver School of Medicine (UCDSM) and Massachusetts General Hospital cautioned.
"Prenatal vitamins do help raise vitamin D levels, but many women start taking them after becoming pregnant," UCDSM's Dr. Adit Ginde said in a news release. "Although research is ongoing, I think it's best for women to start a few months before becoming pregnant to maximize the likely health benefits."
The finding was published in the May issue of the American Journal of Obstetrics and Gynecology.
Although the study did find that some women are getting the vitamin D they need, the authors warned that many are not. Those most at risk are women with darker skin, those living in northern regions during the winter, and those who tend to cover up their skin for religious and/or cultural purposes.
In general, vitamin D levels seem to have been dropping in recent years, the researchers noted -- perhaps due to a dip in outdoor activity. Vitamin D deficiency in the first years of life is associated with a higher risk for respiratory infection and childhood wheezing, while adults who lack an adequate supply bear a greater risk for heart disease and certain cancers.
Testing and supplementation could be the answer to the apparent problem. However, there may be risks from excessive vitamin D intake, the researchers said.
"We need more data from clinical trials of vitamin D supplementation in pregnant women," study co-author Dr. Carlos Camargo, of Massachusetts General, said in the news release. "If the ongoing trials continue to show benefit, the best strategy will likely be measuring vitamin D levels through a simple blood test and choosing supplementation doses according to those levels."
More information
For more on vitamin D, visit the U.S. National Institutes of Health.
