![](https://static01.nyt.com/images/2018/06/02/science/02SEXPAIN/02SEXPAIN-mediumThreeByTwo440.jpg)
By KATIE THOMAS from NYT Health https://ift.tt/2Hhp52X
In two surveys done four years apart, the number of Veterans Affairs hospitals mandating flu shots rose only slightly, from 1 percent in 2013 to 4 percent in 2017, researchers said.
For the study, the researchers examined the vitamin D levels of 1,200 women with a history of miscarriage before they got pregnant again. Their vitamin D levels were also tested when they were eight weeks' pregnant.