Wake Up Refreshed: Uncovering The Connection Between Vitamin D and Sleep

If you're having sleep problems, you may be missing the essential "sunshine vitamin". New research shows a strong link between low levels of vitamin D poor sleep. While most people associate vitamin with bone health, and in some cases immune function, this functional nutrient is also responsible for regulating the body's natural sleep-wake cycle and producing melatonin, which are crucial for getting a good night's sleep. If you're having trouble falling asleep or staying asleep, or just not getting the sleep you want--could vitamin D be the perfect natural sleep aid? 

For the 41% of U.S. adults who are insufficient in vitamin D, and the 29% who are genuinely deficient, anyone looking to improve sleep quality would be smart to start by checking their vitamin D status (1).

Should you test your vitamin D levels? Get started>>

Low vitamin D levels linked with shorter sleep duration, poor quality sleep

Growing evidence links vitamin D with sleep regulation. Vitamin D deficiency can increase risk of sleep disturbances and is associated with shorter sleep duration and nighttime awakenings in children and adults (2).

Other sleep disorders, such as obstructive sleep apnea, have also been associated with lower vitamin D levels.

The average adult needs at least 7 hours of sleep per night.Less than that, and important cognitive and metabolic processes likely aren’t functioning optimally. Coincidentally, one analysis revealed that those who get less than 7 hours have an average daily intake of approximately 178 IU of vitamin D (3). 

That's less than 10% of what's needed to avoid a frank deficiency, and an alarming 3.5% of the necessary daily dosage to achieve more optimal vitamin D levels, which research suggests is a blood level of about 50-60 ng/mL.

Currently, 2,000 IU will prevent an outright deficiency (<20 ng/mL), but this is barely enough for essential bodily functions. A more optimal intake of vitamin D would be about 5,000 IUs daily.

Are you getting the vitamin D you need? Find out.

How vitamin D impacts sleep

As far as sleep quality is concerned, vitamin D functions more like a hormone than a vitamin. To promote healthy sleep, vitamin D acts as a messenger in different areas of the brain, as well as activating various enzymes to promote sleep.

Vitamin D receptors are found in multiple areas of the brain that regulate sleep, including the hypothalamus, suggesting multiple functions along the pathway to quality sleep (2). 

Vitamin D has also been found to have a direct impact on melatonin production, the hormone responsible for encouraging sleep. Vitamin D deficiency has been linked to reduced melatonin levels in both adults and children, which can make it especially hard to fall asleep.

Another theory involves the effect of sunlight. It is well known that vitamin D levels are regulated by exposure to sunlight and since sunlight also affects the circadian rhythm, there's likely a link between those factors.

Related: Are You A Night Owl? Tune Your Sleep Cycle to Slow Aging

Low vitamin D in children and adolescents

Low vitamin D levels can have particularly detrimental effects on children and adolescents, who require adequate sleep for growth and development. Vitamin D supplementation in teens has been found to improve quality of sleep, as well as to reduce daytime fatigue (4).

Vitamin D receptors can also be found in the brain (in the hippocampus, amygdala, and prefrontal cortex) suggesting that vitamin D is also associated with the regulation of mood and emotional behavior in children & teens (5). 

Since the brain regulates sleep and sleep quality and sleep cycles. With children, vitamin D is very important since it impacts brain development and neuronal growth factors.

Learn more: Vitamins for Kids: What’s Really Necessary

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Vitamin D may improve sleep

When it comes to vitamin D intake, it appears getting enough of the “sunshine vitamin” correlates with getting adequate sleep. If you’re not getting enough vitamin D, optimizing your levels may help you sleep better, and for longer.

In a study of individuals who were given vitamin D supplements for 8 weeks, participants reported an improvement in sleep duration, sleep quality, and the time it took to fall asleep (6). 

Adequate vitamin D may also help you clock more restful hours for the time you actually spend in bed. A randomized study found that 3 months of supplementation with 4000 IU of vitamin D resulted in a reduction in the time it took to fall asleep, and an increase in the percentage of time spent asleep during the night (7). 

For those with insomnia, dealing with chronic pain is frequently to blame. And it appears sufficient vitamin D may be able to mitigate pain to improve sleep as well. A study evaluating the effects of 1200 IU/day to veterans with low vitamin D levels (a blood level less than 30 ng/mL) and multiple areas of chronic pain found a decrease in self-reported pain, as well as an improvement in sleep pattern. They were also able to fall asleep faster and stay asleep longer (8). 

About 10% of adults meet the criteria for chronic insomnia. In one study, participants returned to normal sleep cycles with vitamin D levels at 60–80 ng/mL (9). This suggests the need to test vitamin D levels when treating sleep disorders, and that working toward an optimal level is beneficial. 

Related: The Supplement Guide: Health Benefits, Dosages, Facts

Factors that may cause low vitamin D levels

There are lifestyle and genetic factors that play a role in vitamin D levels. For example, working non-standard hours or living at higher latitudes have been linked to both low vitamin D levels and poor sleep quality. Other factors that affect vitamin D include:

  • Age
  • Darker skin color
  • Pregnancy and breastfeeding
  • Menopause
  • Long-term steroid use
  • Inadequate sun exposure
  • Diets low in fish, dairy, and animal proteins
  • Obesity
  • Malabsorption issues (IBD, Celiac, gastric bypass, etc.)

Are you at risk for low vitamin D? Learn more about vitamin D supplements.

Who may benefit from vitamin D supplementation for sleep?

Nearly everyone can benefit from optimizing vitamin D levels, considering that 93% of Americans fail to get in just 400 IU of vitamin D per day from their diet—and the science is clear that we likely need much more than that to reach optimal blood levels (10). 

If you have any of the above risk factors, or if you’re not getting enough sun exposure, then supplementation with vitamin D may be beneficial for your sleep.

How to improve sleep with vitamin D supplementation

Adequate vitamin D helps support not only restful sleep, but a healthy immune system, stable mood, and metabolic function too. Nearly every cell in your body has a receptor for vitamin D, highlighting the importance of its function in maintaining health.

Optimal D3 levels vary quite a lot between populations, so it’s important to get your levels tested prior to supplementing to find out where you’re starting from.

How to supplement with vitamin D: The amount needed to maintain blood levels of 35-50 ng/mL varies, but it’s usually somewhere between 2,000 to 5,000 IU (11). 

Vitamin D status is measured by 25(OH)D in the blood. Get your vitamin D levels tested prior to starting supplementation. Other vitamins and minerals, such as magnesium, and vitamins A, D, and K work synergistically. Adequate vitamin A and K are important to protect against any negative effects of vitamin D supplementation (12).

Is it time to test your vitamin D levels? Learn more about what your doctor should be checking>>

Vitamin D is essential for healthy sleep and should be taken into consideration when looking to improve sleep quality or duration. If you suspect that you may be deficient in vitamin D, speak with your doctor about getting tested and monitoring your levels.


  1. https://www.cambridge.org/core/journals/british-journal-of-nutrition/article/vitamin-d-deficiency-and-insufficiency-among-us-adults-prevalence-predictors-and-clinical-implications
  2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8912284/
  3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6835726/
  4. https://www.mdpi.com/1422-0067/23/3/1430
  5. https://academic.oup.com/nutritionreviews/article/67/8/481/1839131
  6. https://pubmed.ncbi.nlm.nih.gov/28475473/
  7. https://www.annallergy.org/article/S1081-1206(14)00012-X/fulltext
  8. https://journals.lww.com/clinicalpain/Abstract/2013/04000/Improvement_of_Pain,_Sleep,_and_Quality_of_Life_in.9.aspx
  9. https://www.mdpi.com/1422-0067/23/3/1430
  10. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6686054/
  11. https://www.ncbi.nlm.nih.gov/books/NBK56070
  12. https://pubmed.ncbi.nlm.nih.gov/17145139/


Holistic Medicine, sleep, Vitamin D

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