By now, most of us know the basics of how to get good sleep: Stick to a schedule, stop caffeinating early in the day, and keep your bedroom cool and dark. But considering that an estimated one in three Americans still aren’t getting enough rest on a regular basis, researchers continue to investigate new and novel sleep tips. One of the latest to show promise in a scientific review? Supplementing with vitamin D.*

Analyzing the link between vitamin D and sleep.

This meta-analysis published in the journal Nutrients included 19 studies—13 of which were randomized controlled trials, considered a research gold standard. Combined, these studies tracked the vitamin D levels and sleep of 9,397 people of all ages and backgrounds.

In reviewing this body of research, Myriam Abboud, Ph.D., a nutrition researcher at Zayed University in the UAE, found that there did appear to be a link between adequate vitamin D levels (i.e., vitamin D sufficiency) and high-quality rest.* Specifically, those who took a vitamin D supplement scored better on the Pittsburgh Sleep Quality Index—a list of questions that assesses sleep quality over a one-month period.*

“In conclusion, the evidence presented in this review suggests a beneficial role of VDS [vitamin D supplementation] in enhancing sleep quality,”* Abboud writes in the meta-analysis.

This suggests that in addition to other sleep-promoting habits, making sure your vitamin D levels are up to snuff (30 ng/mL is the cutoff for insufficiency to avoid; ideally at least 50 ng/mL) may go on to support your slumber.*

There are a few ways that vitamin D and sleep could be connected. For starters, there are binding sites for vitamin D on nearly every cell in our body—including ones in our brain that affect sleep.* The fat-soluble vitamin also appears to play a role in the production of melatonin—the “hormone of darkness” that tells our bodies when it’s time for bed.* Exposure to sunlight suppresses the production of melatonin but encourages the production of vitamin D, so that’s another potential link.

While researchers are pretty sure that healthy vitamin D levels support healthy sleep (and vice versa), this new analysis notes that we still have more to learn about how exactly vitamin D supplementation plays into things.* However, it’s worth noting that there are plenty of other reasons to take a vitamin D supplement, beyond sleep support.*

Due to factors like diet and geography, many of us don’t get adequate amounts of vitamin D from sunlight and diet alone. Taking a daily supplement of 5,000 IU of vitamin D3 can get levels back to that optimal range—and support bone and muscle health, thyroid health, oral health, and much more in the process.*

The best part is that vitamin D supplements are easy to incorporate into your life. While other restful habits like staying off electronics at night and limiting stress levels take effort, taking a D3 gelcap is something you can basically do in your sleep.

If you’re one of 41% of U.S. adults who are vitamin D insufficient, your sleep quality could be suffering according to a new Nutrients meta-analysis.* Count this as yet another reason to take a daily vitamin D supplement. Here are our top picks.

If you are pregnant, breastfeeding, or taking medications, consult with your doctor before starting a supplement routine. It is always optimal to consult with a health care provider when considering what supplements are right for you.