Vitamin D Benefits for Brain Health & Sleep

Is Vitamin D Hype ‘Wishful Thinking’?

Vitamin D Benefits for Brain Health & Sleep

April 26, 2019 — Vitamin D has been proclaimed a potential protector against everything from cancer, heart disease, and diabetes to mood disorders depression and dangerous falls. But recent research has challenged several of those promising roles and revealed how little is really known about the essential nutrient.

“It’s been a hot topic for about 10 years,” says Kelly Pritchett, PhD, a registered dietitian who studies vitamin D at Central Washington University in Ellensberg, WA. “But there are a lot of different trains of thought about what’s optimal.”

In 2014, the U.S. Preventive Services Task Force, a federally funded panel of health experts, said there was no common agreement on how to define vitamin D deficiency or what level was ideal. That remains the case today.

Still, vitamin D supplements have become more popular. Two decades ago, fewer than 1% of U.S. adults took them, according to a 2017 study. But less than 15 years later, nearly 1 in 5 adults took one every day. Why?

“The bottom line is, there’s a lot of wishful thinking,” says vitamin D researcher Clifford Rosen, MD, the director of clinical and translational research and a senior scientist at the Maine Medical Center Research Institute in Scarborough. “Whatever sounds good is often what people to use.”

While low vitamin D levels have been linked to many health problems — such as a higher risk of some types of cancer, diabetes, heart disease, and depression — research is inconclusive.

Researchers do know that vitamin D helps our bodies absorb calcium, which helps keep bones healthy. So it’s perhaps natural to assume that vitamin D supplements may help strengthen our bones and protect against fractures and falls.

But a large review of the research, published in October, concluded that vitamin D supplements, in low or high doses, play no such role.

“Everybody once thought that it would, but we now have become much more skeptical,” says Rosen. “Supplementation doesn’t increase bone density, so how would it reduce the risk of fractures? The answer is we don’t know. But if your vitamin D levels are sufficient, there’s no rationale for adding more.”

In November, another significant study, funded by the National Institutes of Health, appeared. In this one, researchers recruited nearly 26,000 healthy U.S.

adults over 50 to take either a vitamin D supplement or a placebo.

After following them for an average of almost 5 1/2 years, the study authors concluded that vitamin D supplements did not lower the risk of cancer, stroke, or heart attack.

And in February, researchers published an analysis of past studies on the link between vitamin D supplements and cancer risk and survival.

They found no link between taking a supplement and a lower risk of cancer, but they did connect taking vitamin D supplements to a 13% lower risk of dying from cancer.

The study did not look at whether vitamin D supplements were directly responsible for that drop in the cancer death rate by, perhaps, revving up the body’s immune system to fight the disease.

“Could vitamin D improve the immune system enough that it could improve cancer mortality? The answer is maybe,” says Rosen. “It’s not that I don’t believe it. I think it’s attractive but it needs to be tested in a randomized trial.”

Irina Todorov, MD, a family medicine doctor at the Cleveland Clinic, agrees: “Though there are many, many studies about cancer and heart disease and so on, we need more research to identify whether specific numbers, specific levels may be beneficial.”

Does this new research mean that your vitamin D supplements serve no purpose? Maybe.

“If you have an adequate level, I don’t see that you’ll get benefits from taking a supplement,” says Pritchett.

But getting enough vitamin D through your diet is difficult. “Very few foods are naturally high in vitamin D, unless you’re talking about fatty fish,” she says.

Some foods, milk, are fortified with vitamin D, but even if you drink 3 cups of milk a day, says Pritchett, you’ll still fall far short of the 600 IUs that current recommendations advise for people between the ages of 1 and 70.

The best way to be sure to get enough of the nutrient is to go outside and get some sun. When the sun’s ultraviolet rays hit your skin, that light triggers the production of vitamin D in your body. To benefit, you don’t need to — and, because of skin cancer risk, shouldn’t — sunbathe. Instead, Todorov recommends only 10 to 15 minutes, two to three times a week between 10 a.m. and 3 p.m.

“Expose yourself, then put on your sunscreen,” she says.

Some medical groups disagree with this advice. The American Academy of Dermatology, for example, recommends against getting vitamin D via sunlight because sun exposure can make skin cancer more ly. The preventive services group also says sun exposure is not generally recommended as a treatment.

But she points out that not everyone can do this. Health reasons or your job may keep you indoors. And, as we age, our skin produces less vitamin D. Also, if you live in an area with high pollution or in a part of the world that gets limited sun, your time outdoors may not give you much vitamin D. In those circumstances, a supplement may make sense.

Certain health conditions also can make you less able to meet your vitamin D needs and may make supplements a useful addition to your diet and outdoor activities.

These include Crohn’s disease and celiac disease, as well as liver and kidney diseases. If you’ve had gastric bypass surgery, your body may not absorb nutrients as well as it might have before.

Obesity also has been tied to low levels of vitamin D, but, says Rosen, the reason why remains unclear.

If you have any of those health conditions or other things that raise your risk, says Todorov, your doctor may run tests to see if you have enough vitamin D.

You may also be tested if you have the bone-softening disease osteomalacia or, in children, a similar condition called rickets. Both often result from a lack of vitamin D, which may be treated with vitamin D supplements.

In general, though, such blood tests are not recommended. The Preventive Services Task Force says there’s no evidence that such screenings provide any benefits.

Don’t want to give up your vitamin D supplements while you wait for the experts to answer the many questions about their value? You ly have nothing to worry about as long as you go easy on them. Getting too much vitamin D can bring nausea, vomiting, fatigue, and other unpleasant symptoms caused when vitamin D leads to the production of too much calcium in your body.

“I don’t think there’s any harm in doses up to 4,000 IUs a day,” says Rosen, “but you have to be realistic that it’s unly to have an impact on most chronic diseases.”

Kelly Pritchett, PhD, registered dietitian, Central Washington University, Ellensberg, WA.

Clifford Rosen, MD, director of clinical and translational research and senior scientist, Maine Medical Center Research Institute, Scarborough.

Irina Todorov, MD, Center for Integrative Medicine, Cleveland Clinic.

The Lancet: Diabetes & Endocrinology: “Effects of vitamin D supplementation on musculoskeletal health: a systematic review, meta-analysis, and trial sequential analysis.”

Cleveland Clinic: “Vitamin D & Vitamin D Deficiency.”

Annals of Oncology: “Vitamin D supplementation and total cancer incidence and mortality: a meta-analysis of randomized controlled trials.”

New England Journal of Medicine: “Vitamin D Supplements and Prevention of Cancer and Cardiovascular Disease.”

NIH Office of Dietary Supplements: “Unit Conversions.”

Journal of the American Medical Association: “Trends in Use of High-Dose Vitamin D Supplements Exceeding 1000 or 4000 International Units Daily, 1999-2014.”

U.S. Preventive Services Task Force: “Final Recommendation Statement: Vitamin D Deficiency: Screening.”

© 2019 WebMD, LLC. All rights reserved.


Vitamin D Benefits for Brain Health & Sleep

Vitamin D Benefits for Brain Health & Sleep

Though vitamin D is famously known as the “sunshine vitamin,” it might be just as important for the body and mind during nighttime.

Research suggests sunlight gives us a boost of vitamin D during the day to support our energy levels, balanced mood, and mental health. During the night, healthy vitamin D levels help the brain get restful sleep.

Read on to learn more about vitamin D’s relationship with the brain.  

Vitamin D, Brain Health & Sleep Snapshot

  • Healthy vitamin D levels contribute to quality sleep
  • Vitamin D supports brain health and development
  • Low vitamin D levels have been linked with cognitive problems and depression
  • Supplementation may be beneficial in people who are deficient

The body naturally makes vitamin D when exposed to sunlight. Getting regular, moderate sun exposure is a safe way to maintain normal vitamin D levels during the summer months.

Vitamin D is also found in certain foods, such as fatty fish salmon and sardines. Additionally, many vitamin D supplements are available on the market.

Taken at the recommended doses, vitamin D supplements are considered safe. However, taking too much can be harmful. Vitamin D supplements may also interact with prescription medications. Remember to talk to your doctor before supplementing!

Vitamin D May Improve Sleep Quality

Vitamin D levels may play a role in sleep disorders [1].

In one study, higher concentrations of this vitamin were associated with better maintenance of sleep [2].

In the National Health and Nutrition Examination Survey (NHANES) study, lower vitamin levels were associated with shorter sleep duration [1].

Some studies suggest improved sleep quality with vitamin D supplementation. It has been hypothesized that deficiency is central to a recent “epidemic” of disturbed sleep patterns, though large-scale studies are needed to confirm these findings [3].

One study reported a high prevalence of vitamin D deficiency in people with obstructive sleep apnea. This is a widespread disorder characterized by episodes of breathing cessation due to upper airway tract obstruction during sleep. Deficiency is more pronounced in severe sleep apnea and associated with abnormal glucose production [4, 5, 6].

More studies are needed to prove the relationship between sleep quality and vitamin D supplementation.

Vitamin D Supports Brain Health & Development

Some scientists view vitamin D as a hormone active in the brain or neurosteroid [7, 8].

The vitamin D receptor (VDR) and the enzyme responsible for the synthesis of the active form of this vitamin are present in the brain [9, 10, 11].

Studies indicate that this vitamin is important for brain development, while deficiency has been associated with a wide range of psychiatric and neurological diseases [7, 12, 13, 14].

Limited research suggests that vitamin D may protect brain cells by activating detoxification pathways (production of the antioxidant glutathione, inhibition of nitric oxide). Furthermore, some scientists believe that it also helps produce proteins that increase the survival of brain cells in the aging brain and in neurological diseases (neurotrophins). More research is needed [15, 16, 17].

According to epidemiological studies, low concentrations of vitamin D are associated with:

  • impairments in cognitive function such as memory and orientation problems [18, 19, 20].
  • diagnosis of dementia and Alzheimer’s disease [21].
  • higher rates of psychotic experiences and schizophrenia [22, 23, 24].
  • depressive symptoms [25, 26, 27].

However, clinical studies have yet to determine the safety and efficacy of supplementation in people with cognitive, neurological, and mental health problems.

Effects on Cognitive Function

Studies suggest that low levels of blood vitamin D are associated with low mood, impaired cognitive functions, and dementia [20, 19, 28, 18].

However, other studies suggest that supplementation doesn’t influence cognitive or emotional functioning. In one study, supplementation of 5,000 IU/daily of this vitamin for 6 weeks did not have beneficial effects on memory, depression, anxiety or anger [29, 30].

Effects on Mood & Depression

In two studies, vitamin D deficiency was associated with an 8 – 14% increase in the prevalence of depression and a 50% increase in suicide rates. Large-scale studies are needed to confirm these findings [31, 32].

According to limited research data, supplementation may reduce depressive symptoms and improve physical functioning in patients with depression [33, 34].

However, other studies revealed that supplementation neither worsened nor improved depressive symptoms. In a study of elderly postmenopausal women, vitamin D and hormone therapy had no effect on depression, individually or in combination [35].

May Reduce the Risk of Parkinson’s Disease

Some scientists hypothesize that vitamin D deficiency may contribute to the development of Parkinson’s disease. They determined deficiency early in the disease, and vitamin levels tend to decline further as the disease progresses [36, 37, 38].

Additionally, scientists posit that chronically inadequate intake of this vitamin leads to a loss of dopaminergic neurons in the substantia nigra, the region of the brain affected most by Parkinson’s disease [38, 39, 40].

However, these studies had small samples and the above-mentioned theories remain speculative. Large-scale studies should replicate their findings.

Other research teams suggest that maintaining normal vitamin D levels might reduce the risk of Parkinson’s disease, though their findings are also far from conclusive. In one study, higher vitamin D blood levels were associated with reduced risk of developing Parkinson’s disease. People with blood levels of at least 50 nmol/l had a 65% lower risk than those with values under 25 nmol/l [39].

In another study, patients with Parkinson’s disease were more ly to have an insufficiency of this vitamin compared to age-matched patients with Alzheimer’s disease. Further studies should include more people and compare their blood levels to healthy controls over a period of time [36, 37].

Plays a Role in Alzheimer’s Disease

Similar to the theory mentioned above, some scientists suspect that vitamin D deficiency is prevalent in Alzheimer’s disease and dementia patients. In a couple of studies, Alzheimer’s disease patients had lower blood levels of this vitamin compared to age-matched healthy individuals [41, 42].

In one study, blood levels of this vitamin under 50 nmol/L were associated with a higher risk of Alzheimer’s disease and dementia [43].

Though these findings are promising, additional studies are needed to determine the link between vitamin D deficiency and Alzheimer’s disease. Ideally, future studies should also take genetic factors (including APOE4 genotypes) into consideration.

Animal and cell-based studies suggest that vitamin D may prevent Alzheimer’s by stimulating immune cells to break down built-up amyloid-β in the brain, which plays a causative role in the disease. Human studies have not confirmed these findings [44, 45].

Read More


Have Trouble Sleeping? Increasing Vitamin D Can Help

Vitamin D Benefits for Brain Health & Sleep

After a cold and snowy winter, at least here in Boston, spring has finally sprung! For many, that means the sun is shining and it’s time to do some spring cleaning. And our favorite type of cleaning starts in the kitchen with the cabinets. It’s the perfect time of year to focus on cleaning up your diet, and is peak season for soaking up some sunshine and vitamin D!

But did you know that the “sunshine vitamin” plays a big role in your night, too? If your vitamin D levels are on the lower end, it could actually be affecting your sleep. Worry not, though! Below, we’ll go over the evidence behind the effect vitamin D has on sleep and give you some suggestions for your best night of rest yet

The science

Several studies have shown an association between vitamin D levels and different measures of sleep. Low blood levels of vitamin D are associated with decreased sleep time, decreased sleep efficiency, and increased daytime sleepiness.1,2,3,4

  • Sleep time is simply the amount of time that you sleep
  • Sleep efficiency is a measure of sleep the time it takes you to fall asleep and how many times you wake throughout the night
  • Daytime sleepiness is a subjective measure of how sleepy/tired a person felt throughout the day

In short, these studies concluded that if your vitamin D is low you might sleep less, and even when you do sleep, it may be less efficient, less restful sleep. Translation? You’ll be sleepy the next day.

Furthermore, another study showed that improving vitamin D levels by taking a supplement improved sleep. This is important because it is one thing to say that low vitamin D is associated with undesirable sleep measures, but another to show that increasing vitamin D actually improves sleep.

A randomized, controlled trial is needed to show a direct relationship between vitamin D and sleep. In this randomized, controlled trial study by Huang et al., patients were given supplements their vitamin D status. Overall, their vitamin D status improved from a mean of 18.

57 ng/mL up to 26 ng/mL post-intervention, and their sleep time increased by about 45 minutes.4

Several studies even saw a dose-dependent relationship between vitamin D levels and sleep.1,2 This adds to the evidence that there is a direct, linear relationship between vitamin D and sleep measures.

This also means that improving your vitamin D by any amount will improve your sleep.

While reaching your optimal zone will result in the best sleep, just improving your vitamin D even just a little bit could improve your sleep by the same amount.

How it works

Without getting too technical, researchers have found that there are vitamin D receptors on certain brain areas that control sleep.

They hypothesize that your level of vitamin D affects sleep by binding to these receptors.

5,6 If you have lower levels of vitamin D, theoretically you would have less vitamin D binding in the brain, and these brain areas may work a little differently than if you had a lot of vitamin D bound.

InsideTracker Optimal Zones

The InsideTracker vitamin D optimal zone ranges from 40 to 100 ng/mL. As long as your vitamin D level falls between these numbers, your sleep is as optimized as it can be in regards to vitamin D! An important note, though, is that a lot of other factors also affect sleep.

Here, we are focusing on vitamin D specifically, but good sleep is a combination of a lot of things both internal and external to your body/biomarkers, and we would never claim that optimizing your vitamin D level is going to fix all of your sleep problems overnight.

However, if your vitamin D is below optimal and you want to improve your sleep, increasing vitamin D could be a great first step.

Sources of vitamin D

The strongest source of vitamin D comes from the sun. When the sun hits your skin, the UVB rays react with a molecule in your skin and synthesize vitamin D. These reactions can be inconsistent, though, and factors skin pigmentation, use of sunscreen, and the strength of the sun all affect the amount of vitamin D that you make.

If it is difficult for you to get vitamin D from the sun, you can also get it from food. Dietary sources of vitamin D include:

  • Fatty fish such as salmon, tuna, and mackerel
  • Fortified dairy and dairy alternatives

You can find many more options for food sources of vitamin D using InsideTracker’s new nutrition page.

Vitamin D supplements are another great option that can give you that extra boost. In fact, vitamin D supplements are the most commonly used supplements among our InsideTracker users. Check out a recent blog we wrote on how to safely choose a supplement.

Because vitamin D plays a large role in the body, but can be difficult to get, testing your vitamin D level is very important! Testing takes the guesswork your health so you can take control and see exactly how your dietary changes affect your biomarkers. Test your vitamin D with us and receive a personalized set of recommendations for how to optimize your levels.

Some other blog posts we think you'll love:


  1. [1] Beydoun MA, Gamaldo AA, Canas JA, Beydoun HA, Shah MT, McNeely JM, Zonderman AB. “Serum nutritional biomarkers and their associations with sleep among US adults in recent national surveys.” PLoS One. 9.8(2014).
  2. [2] Massa J, Stone KL, Wei EK, Harrison SL, Barrett-Connor E, Lane NE, Paudel M, Redline S, Ancoli-Israel S, Orwoll E, Schernhammer E. “Vitamin D and actigraphic sleep outcomes in older community-dwelling men: the MrOS sleep study.” Sleep. 38.2(2015): 251-257.
  3. [3] Hansen AL, Dahl L, Olson G, Thornton D, Graff IE, Froyland L, Thayer JF, Pallesen S. “Fish consumption, sleep, daily functioning, and heart rate variability.” J Clin Sleep Med. 15.10(2014): 567-575).
  4. [4] Huang W, Shah S, Long Q, Crankshaw AK, Tangpricha V. “Improvement of pain, sleep, and quality of life in chronic pain patients with vitamin D supplementation.” Clin J Pain. 29.4(2013): 341-347.
  5. [5] Musiol IM, Stumpf WE, Bidmon HJ, Heiss C, Mayerhofer A, Bartke A. “Vitamin D nuclear binding to neurons of the septal, substriatal, and amygdaloid area in the Siberian hamster (Phodopus sungorus) brain.” Neuroscience. 48.4(1992): 841-848.
  6. [6] Gominak SC, Stumpf WE. “The world epidemic of sleep disorders is linked to vitamin D deficiency.” Med Hypotheses. 79.2(2012): 132-135.


When to Take Vitamin D: How Vitamin D Affects Sleep

Vitamin D Benefits for Brain Health & Sleep

  • Low vitamin D levels affect your entire body, including your sleep.
  • Researchers aren’t sure how vitamin D affects sleep (yet). What we do know is that raising vitamin D levels is associated with better sleep quality.
  • Keep reading to find out when to take vitamin D, plus tips to naturally increase your levels.

You might know that a large percentage of the U.S. population is low in vitamin D. What you may not know is that low vitamin D levels can lead to insomnia and other sleep disorders — yikes. Unless you have access to adequate sun exposure, taking a vitamin D supplement is an easy way to get your levels up.

However, there are nuances to when to take vitamin D and how much to take. Here’s what you need to know.

Learn why you're not sleeping and find out how to wake up feeling refreshed. Enter your email to get your free guide!

Vitamin D and sleep

More than half of the world population is deficient in vitamin D.[1] That’s a problem because your body uses vitamin D for every system in your body, from maintaining bone health to supporting immunity. Low levels of vitamin D are directly related to the amount and quality of sleep you’re getting.

Rodent studies have found vitamin D receptors in the parts of the brain that regulate sleep.[2] [3] Clinical studies (in people) have found that low levels of vitamin D are associated with poor sleep quality. In one uncontrolled study, participants who brought up their vitamin D levels saw significant improvement in sleep and neurologic symptoms [4]

In another study,[5] researchers looked at the vitamin D levels and sleep quality of 3,048 men 68 years and older.

They measured total sleep time, wake times and frequency and “sleep efficiency,” which measures the time spent in bed versus the time spent sleeping.

The study found that low levels of vitamin D were related to poor quality sleep and sleeping less than 5 hours a night. Low levels were also associated with lower sleep efficiency scores.

We’re just beginning to understand how vitamin D plays a role in sleep.

In a 2017 study of vitamin D and sleep quality in hemodialysis patients, researchers suggest that vitamin D may affect your shut-eye by interacting with the areas of the brain thought to regulate sleep.

On the other hand, vitamin D plays a key role in supporting your immune system, and managing inflammation may support better sleep quality.

And the amount isn’t the only thing that matters: You should also pay attention to when you take vitamin D.

Early research suggests vitamin D is inversely related to melatonin, your sleep hormone.[6] This means that increasing vitamin D levels may suppress melatonin levels.[7] So, it makes sense that taking it at night could disrupt your sleep.

I’ve noticed this effect personally. When I’ve taken vitamin D in the morning I had my usual great sleep. When I’ve taken it before bed, I had a restless night. Part of being Bulletproof is paying attention to how small changes make you feel. If you take vitamin D before bed, pay attention to how refreshed you feel the next day.

The other benefit of taking vitamin D in the morning: this is a fat-soluble vitamin, which means it’s best absorbed when you take it with food. Have it with breakfast or a cup of Bulletproof Coffee when you take your other supplements. That’s one more thing to cross off your to-do list.

Related: How to Sleep Better: Science-Backed Sleep Hacks to Wake Up Ready to Go

Start hacking your sleep with vitamin D

If you are unsure of where to start, get your baseline levels. Ask your doctor for updated vitamin D tests every six months or so.

You can also test your levels at home using a self-testing service WellnessFX.
The recommended daily amount of vitamin D is 600 IU (15 micrograms) for those between the ages of 1 to 70.

[8] If your levels are low, learn how to get more vitamin D — plus other reasons to up your intake.

Find out how to get the best sleep ever with the Bulletproof Sleep Roadmap. Enter your email to download your free copy!

Learn why you're not sleeping and find out how to wake up feeling refreshed. Enter your email to get your free guide!

This is an updated version of an article originally published Sept. 2012.


Does vitamin D help you to sleep?

Vitamin D Benefits for Brain Health & Sleep

Vitamin D, though usually regarded as a nutrient, is also classified as a prohormone1 – this means that it’s a substance that your body can convert into a hormone. Vitamin D is important for a number of bodily functions; it helps to support your immune system and it’s vital for the absorption of calcium, promoting strong and healthy bones.

There are vitamin D receptors all over your body, including your immune cells and the part of your brain responsible for regulating your sleep cycle. However, what most people don’t realise is that there are different forms of vitamin D – vitamin D2 and vitamin D3

The main difference between these two forms seems to be their sources. Vitamin D3, which is arguably the most effective form for raising your overall levels of vitamin D, is synthesised from sunlight and only found in animal-derived food products such as oily fish. Vitamin D2 on the other hand, is often used to fortify foods and is found mainly in plant-based foods such as mushrooms.

Unfortunately, vitamin D deficiencies are extremely common in the UK. As I’ve mentioned, vitamin D3 is mainly produced from sunlight and, if you happen to be enjoying the bleak autumn weather here in the UK, then I’m sure you’re already aware that, with the days growing shorter, your chances of soaking up the sun are rapidly diminishing.

Can low levels of vitamin D affect your sleep?

Vitamin D deficiency in the UK is a real problem and Public Health England has even recommended that the public seriously consider taking a supplement during the winter months.

2  Low levels of this nutrient can be associated with a variety of symptoms, some of which are definitely capable of impacting your sleep  indirectly.

Below are just a few of the more common side effects of not getting enough of the ‘sunshine’ vitamin:

As you can see that’s quite the list of problems that low levels of vitamin D are responsible for. Certainly, if you’re catching colds, suffering from achy joints or mood problems, then it isn’t too far of a stretch to say that your sleep will be impacted. 

However, so far this link between low levels of vitamin D and poor sleep has been observational but more recently, a study has emerged that seems to have given more credence to the idea that vitamin D can influence sleep quality.

The study, which involved 3048 male participants over the of 68, measured both vitamin D serum levels and sleep, recording total sleep time, sleep efficiency, wake time and disturbances.

Out these 3048 participants, around 16% already had low levels of vitamin D.

The results reveal that low vitamin D increased the lihood of experiencing insufficient sleep and were linked to lower sleep efficiency scores.3 

What separates this study from other similar trials in the past is that this study was far more impartial in its approach and measured the results using survey data and objective tools. Of course, that’s not to say it doesn’t have its limitations – it was looking at a very specific age range and gender – but it is promising and it’s hoped that it will lead to wider study in this area.

Do vitamin D supplements help to improve sleep?

Okay, so we’ve established as far as we can that there is a link between low levels of vitamin D and sleep. It therefore makes sense that most people might jump to the conclusion that, if low levels of vitamin D are the problem, then surely taking a supplement to increase your levels of vitamin D will help?

One small double-blind trial conducted in Iran seems to suggest that supplementing with vitamin D may help sufferers. The study involved 93 people between the ages of 20 and 50 and volunteers were assessed using the Pittsburgh Sleep Quality Index (PSQI), a questionnaire that measures sleep quality and disturbances.4 

Those in the vitamin D group received an extremely high dose of 50,000 IU vitamin D3 supplement, with one dose every two weeks, working out at around 3571IU a day. At the end of the study, compared to the placebo group, the participants taking vitamin D3 spent longer asleep and it took them less time to fall asleep too.

While these results are positive, it’s important to remember that this was a very small study and the dose given to most participants is far too high considering that most guidelines recommend taking no more than 600-1000IU of vitamin D3 a day!

What can you take away from these studies?

These studies do reveal that there are positive signs that taking a vitamin D3 supplement could help to support your sleep cycles and certainly, during the darker winter months, it might be a good idea for other reasons too! However, it’s important to realise that these preliminary studies are just that, preliminary. Wider research into this area is still needed and, in the meantime, if you do decide to try a vitamin D supplement, it’s important you opt for the right one.

In her blog, ‘Are you getting too much vitamin D?’ our Nutritionist Emma discusses the dangers of vitamin D toxicity. The problem is that people often assume that more means better and this isn’t always the case. Too much vitamin D might be just as detrimental to your sleep patterns as too little – you need to get the right balance. 

Many of the vitamin supplements available in supermarkets and health food stores don’t seem to implement this idea though and offer supplements that contain far, far too much vitamin D.

Remember, Public Health England are recommending 10mcg supplements during the winter months! Our Balance Mineral Drink provides 100% of your NRV of vitamin D3 and helps to fight fatigue so it might be a nice addition to your daily routine.

During the warmer summer months, supplementing might not be so necessary so try to focus on getting the vitamin D you need from sun exposure and your diet. 






Here in the Pacific Northwest we love talking about the sun! We grumble about it being hidden away behind heavy rain clouds for months at a time in the winter; we delight in the first breakthrough rays in the spring, realizing our pagan longing for it, watching, as if for the first time, as everything around us wakes up from a deep slumber; we marvel at its delightful, almost intoxicating warmth in the early summer; and yes, we find it irritating when the temperature goes a dash over 80 degrees, or if stays too hot for too long into the fall. Our enthusiasm for the sun’s activities makes sense – after all, humans have evolved to rely on sunlight and center many of our activities around its presence. And we Oregonians, are no different.

The “Sunshine Vitamin”

Not un stimulating photosynthesis in plants, inside our human bodies sunlight sets in motion a series of biochemical events that are essential to our wellbeing.

Proclaimed as a vitamin, vitamin D is actually a precursor to a fat-soluble hormone – a substance that our skin produces in response to being out and about, all the while soaking up those rays of sun.

Vitamin D is best known to keep our bones healthy and strong by helping to assimilate calcium from our diet into skeletal tissues.

And it does so much more! At the DNA level, the active form of vitamin D regulates the expression of hundreds of genes, turning them on or off at precisely the right time.

It’s no wonder that if humans don’t get enough of this “sunshine vitamin”, deficiencies can be linked to or exacerbate a variety of disorders, such as seasonal affective disorder, mania [1], psychosis [2], depression [3], metabolic syndrome [4], irritable bowel disease [5], chronic back pain [6], increased severity of PMS symptoms [7], and sleep disorders [8].

Shining Some Light on Low Vitamin D

Emphasized by dermatologists, the danger of ultraviolet radiation is now embedded into our psyche. Going out into the fierce midday light without first slathering on full-strength sunscreen feels plain wrong.

We have become really good at blocking harmful sun’s rays to prevent solar souvenirs that can angrily inflame our skin. However, at the same time it is also so easy to forget about those pathways that are nourished by sunlight. Vitamin D biosynthesis is one such pathway.

Without adequate doses of unblocked sunlight, foods fortified with the vitamin or just straightforward supplementation, one risks falling into the low vitamin D zone. Unfortunately, there is no one symptom that indicates an overt vitamin D deficiency.

But one way that such a deficiency can manifest is through sleep disturbances.   

Vitamin D and Sleep

Sleep is something we often take for granted and discuss frequently in the context of its absence. After all, humans are wired that way – we have a physiological need to sleep. And when we don’t get enough good quality sleep, we just don’t feel right. What many folks don’t realize is just how important vitamin D is for sleep.

In a recent study, sleep quality was assessed in participants with sleep disorders. The authors reported that vitamin D improved sleep quality, reduced sleep latency, raised sleep duration and improved subjective sleep quality [9]. This and other studies highlight the important and powerful connection between vitamin D and sleep [10, 11, 12, 13, 14, 15].

Vitamin D and Melatonin

The mechanism of exactly how vitamin D contributes to a healthy slumber is not quite elucidated; however, clinical science is just beginning to address this enigmatic process.

At least in part, it appears that it might have something to do with vitamin D’s regulation of tryptophan hydroxylase (TRPH) expression – the rate-limiting enzyme in serotonin (and consequently melatonin) production [16].

Vitamin D potentiates the expression of neuronal TRPH to stimulate the appropriate production of serotonin in the brain [17, 18]. Without sufficient serotonin production, melatonin levels will not rise appropriately to give the body that signal to go to sleep at night.

How to Get Enough Vitamin D

A balanced approach to direct sun exposure (too much sun is damaging to skin cells and can increase the risk of skin cancer), eating foods rich in vitamin D (eggs, liver, fatty fish, red meat), and maybe even supplements may be helpful for people who are looking to increase their vitamin D levels. Whether to choose supplements or sunlight to get your vitamin D quota might be worth discussing with your doctor. Vitamin D adequacy can easily be assessed by a simple blood spot test.


[1] Altunsoy, N., et al., Exploring the relationship between vitamin D and mania: correlations between serum vitamin D levels and disease activity. Nord J Psychiatry, 2018: p. 1-5.

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