About 4 in 5 African American women have low levels of vitamin D—though this doesn’t necessarily cause health problems . Now a new study of more than 1,600 African American women in Detroit has shown that two big factors affected participants’ vitamin D levels: whether they took a supplement, and what kind of birth control they used.

Vitamin D supplements FTW

About 40% of women in the study were taking some kind of vitamin D supplement. These women consistently had higher levels of vitamin D, though their levels varied—from 14% to 77% above the average—depending on the dose of vitamin D in their supplement and how often they took it.

The upside of estrogen

About 14% of women in the study were using a birth control that contained estrogen like the pill , the patch , or the ring . Without taking supplements, these women had levels of vitamin D 20% higher than the average level of women in the study. Women using birth control without hormones or a method containing only progestin didn’t show increases in their vitamin D levels.

If you’re worried about the D…

Lots of factors go into choosing your method of birth control, and its effect on your vitamin D may not be your biggest concern. But it’s always nice to know if a method you’re considering has health benefits ! Plus, if you’ve been using a method with estrogen and decide to stop or switch methods, it could be good to keep an eye on your vitamin D levels.

BTW, your health care provider can be a great resource for figuring out whether you need to worry about vitamin D and what your best options are for boosting your vitamin D levels if needed. Diet, supplements, sun, birth control—so many ways to take good care of yourself.