If You're Not Getting Enough Of This Vitamin, Your Sleep Could Be Suffering*

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 Americans1 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 D2.*

This meta-analysis published in the journal Nutrients2 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.

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 melatonin3—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 health4, thyroid health5, 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 insufficient6, 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.