Vitamin D is key to the body’s ability to create melatonin, notes Lindsay Christensen, MS, CNS, LDN, a functional nutritionist in Conifer, Colo. Many of her clients use sleep trackers, and they’ve found that when their vitamin D levels improve — whether through sun exposure or supplementation — their feedback will often show a significant improvement in their sleep quality.
Recent research corroborates Christensen’s findings. A 2018 meta-analysis found that levels of vitamin D lower than 20 ng/mL (nanograms per milliliter) were associated with a 60 percent greater risk of poor sleep.
And in a randomized controlled trial published in 2017, participants with sleep disorders reported significant improvements in several measures of sleep after taking a megadose of 50,000 IUs of vitamin D3 every other week for eight weeks.
“Lack of vitamin D can lead to an increase in inflammatory substances in the body that can interfere with sleep processes.”
This may all be traced back to inflammation, suggests nutritionist Karman Meyer, RD, LDN, author of Eat to Sleep. “Lack of vitamin D can lead to an increase in inflammatory substances in the body that can interfere with sleep processes.”
Emerging evidence suggests that vitamin D may enhance immune health by limiting the release of inflammatory substances, such as prostaglandin D2, tumor necrosis factor alpha, and cytokines. Other research has shown a correlation between a well-regulated immune system and quality sleep.
Whole-Food Sources: Daily exposure to sunshine is the best way to get vitamin D. Egg yolks, wild salmon, sardines (with skin and bones), and mushrooms that have been treated with UV light (look for a label stating this) are among the few food sources for this important vitamin. Note that mushrooms supply vitamin D2, whereas sunlight and animal foods supply D3; the latter more effectively raises serum levels of vitamin D. (For more on this nutrient, see “Vitamin D: What You Need to Know“.)
Supplements: Vitamin D3 supplements are extremely helpful for those living at latitudes where there is less sunlight in winter.
This was excerpted from “Which Nutrients and Supplements Can Help Me Sleep?” which was published in the October 2022 issue of Experience Life.