Vitamin D for Better Sleep?

Seasonal insomnia typically strikes at about this time of year. As the days get shorter, we’re exposed to shorter periods of sunlight, which can alter circadian rhythms and interfere with sleep.

A related problem has to do with our need for vitamin D, which may not be met in low sunlight conditions. Recent publications explore the effects of low levels of vitamin D on sleep, making supplements a good option in the cold weather.

Seasonal insomnia may be driven by vitamin D deficiencySeasonal insomnia typically strikes at about this time of year. As the days get shorter, we’re exposed to shorter periods of sunlight, which can alter circadian rhythms and interfere with sleep.

A related problem has to do with our need for vitamin D, which may not be met in low sunlight conditions. Recent publications explore the effects of low levels of vitamin D on sleep, making supplements a good option in the cold weather.

A Relationship Between Sleep and Vitamin D

It’s well established now that lack of exposure to sunlight has a negative effect on sleep. Interest in the relationship of vitamin D to sleep is relatively new, yet preliminary evidence suggests that low levels of D are associated with short sleep duration, a frequent complaint of people with insomnia. A recent meta-analysis of studies of vitamin D deficiency and sleep disorders also found an association between low levels of D and poor sleep quality.

Levels of vitamin D fluctuate seasonally. Our bodies make most of the vitamin D we need when our skin is exposed to sunlight, and typically there are fewer opportunities for sunlight exposure in the colder months of the year. Thus insufficient vitamin D could be a factor in seasonal insomnia.

Vitamin D Supplements: Will They Improve Sleep?

While a few studies document improved sleep as a result of higher levels of vitamin D, a causal relationship between vitamin D supplementation and better sleep has not been definitively established. However, for a host of health reasons including sleep — avoidance of infectious, autoimmune and neurological diseases, as well as neuromuscular disorders and increased pain sensitivity — vitamin D deficiency is a condition we should try to avoid.

It’s a good idea to pay attention to recommended dietary allowances — expressed in international units (IU) per day — especially in the wintertime. They were established by the Institute of Medicine based on vitamin D’s importance to the development and maintenance of healthy bones. Subsequently the Endocrine Society established recommended dietary allowances for people at risk for vitamin D deficiency. Here’s a table showing both sets of guidelines for daily intake of vitamin D:

Infants Ages 1–18 years Ages 19–70 years Ages 71 & older
Institute of Medicine 400 IU/day 600 IU/day 600 IU/day 800 IU/day
Endocrine Society 400-1000 IU/day 600-1000 IU/day 1500-2000 IU/day 1500-2000 IU/day

Foods Containing Vitamin D

Up to 80% of our D requirement may come from the complex metabolic processes triggered with exposure of the skin to sunlight. But we also get vitamin D from a limited number of foods. Some foods naturally contain D and other foods are fortified with it. Here are some common foods containing vitamin D and approximate amounts:

  • 3.5 oz salmon, fresh (wild): 600–1,000 IU
  • 3.5 oz salmon, fresh (farmed): 100–250 IU
  • 3.5 oz salmon, canned: 300–600 IU
  • 3.5 oz sardines, canned: 300 IU
  • 3.5 oz mackerel, canned: 250 IU
  • 3.5 oz tuna, canned: 236 IU
  • 3.5 oz shiitake mushrooms: 100 IU
  • 1 egg yolk: 20 IU
  • 3.5 oz beef liver, braised: 12–30 IU
  • 8 oz fortified milk or yogurt: 100 IU
  • 8 oz fortified orange juice: 100 IU
  • 3 oz fortified cheese: 100 IU

Breakfast cereals and soy products are also often fortified with vitamin D.

At Risk for Vitamin D Deficiency

You’re more likely to have low levels of vitamin D in these conditions:

  • You get little exposure to sunlight. This may occur if you live in a northerly latitude, spend all or most of your time indoors, habitually wear clothing covering your entire body or cover up with sunscreen all the time. (An SPF of 30 or higher, which confers important protection from cancer, decreases vitamin D synthesis in the skin by more than 95%.)
  • You have dark skin. Dark skin confers natural protection from harmful radiation from the sun but also makes it harder to synthesize vitamin D. Longer periods of sun exposure are required for sufficient vitamin D production to occur.
  • You’re vegan. Most natural sources of vitamin D are animal based.
  • You’re obese. Individuals with a body mass index of 30 or higher often have low blood levels of vitamin D.
  • You’re pregnant or lactating. Pregnant and lactating women may have decreased levels of vitamin D as well.
  • You’re older and have a history of falls and/or fractures. Older adults are somewhat less efficient at synthesizing vitamin D via sunlight exposure.

Vitamin D Supplementation

To remedy low levels of vitamin D, or to maintain adequate levels throughout the winter, take a vitamin D supplement. Take your daily supplement with a meal containing fat, as this will increase vitamin D absorption.

Supplementation and adequate exposure to sunlight (or bright light supplied by a light box) at the approach of the holidays and through the winter may help to protect you from the bane of seasonal insomnia.

Anniversary Book Giveaway Marks Change in Blog

It’s time for a couple of announcements: The Savvy Insomniac came out four years ago today and we’re giving away 10 copies of the book to mark the occasion. Read on to find out how to get one yourself!

Announcement No. 2: I’ve been blogging weekly about insomnia for five years and now, starting in October, I’ll be posting once a month. I’m as committed as ever to offering news and perspective on issues related to sleep and insomnia. But other projects are calling and taking more time.

Here are the giveaway details. After that, a summary of popular blog topics you’ll hear more about in the future.

Still blogging about insomnia—now, once a month

It’s time for a couple of announcements: The Savvy Insomniac came out four years ago today and we’re giving away 10 copies of the book to mark the occasion. Read on to find out how to get one yourself!

Announcement No. 2: I’ve been blogging weekly about insomnia for five years and now, starting in October, I’ll be posting once a month. I’m as committed as ever to offering news and perspective on issues related to sleep and insomnia. But other projects are calling and taking more time.

Here are the giveaway details. After that, a summary of popular blog topics you’ll hear more about in the future.

Book Giveaway

First, heartfelt thanks to those of you who follow my blog. It’s one thing to visit a website now and then but quite another to sign up for news from a blogger who posts a 600- to 800-word story every week! Your interest in insomnia and insomnia treatments must be as deep and personal as mine.

For all the blogging I’ve done about sleep and insomnia, though, The Savvy Insomniac is the best and most comprehensive writing I’ve done on the subject. Anyone living in the US who hasn’t got a copy and wants one can use the contact form to let me know. The first 10 people who contact me with a question about sleep or insomnia (something you wonder about but haven’t found much information about) will get a copy of The Savvy Insomniac free of charge.

Don’t forget to include your mailing address. Overseas shipping rates are so exorbitant that I can’t ship books abroad. But inexpensive e-books continue to be available through Amazon and other online booksellers.

Here, now, are the blog topics most popular with Savvy Insomniac readers. Count on hearing more about them in the months ahead.

Insomnia Relief in the Form of a Pill

Sleeping pills don’t get great press these days, but they have great interest for Savvy Insomniac readers. Posts about Belsomra, the newest sleeping pill approved for the treatment of insomnia, consistently get the most views. Belsomra acts as a sedative by blocking transmission of orexin, a neurochemical that promotes arousal. Other orexin-blocking sleeping pills are in the works. I’ll write about them if and when they’re approved by the FDA.

Posts about sedating antidepressants are also popular. Since many sleeping pills have undesirable side effects, persistent insomnia is sometimes treated with low doses of a sedating antidepressant. Doxepin has been approved as Silenor for treatment of sleep maintenance insomnia. The others (trazodone, mirtazapine, amitriptyline) have not been sanctioned by the FDA as effective for insomnia. They do, however, have sedative properties.

Melatonin supplements are also of high interest to readers, especially in timed-release formulations. But melatonin is not a sleeping pill. Its usefulness lies in its ability to shift the timing of sleep. Melatonin is sometimes recommended to night owls whose daytime schedules make it necessary to go to sleep earlier than they would following their natural inclinations. It also helps lessen jet lag.

Insomnia: What’s Your Flavor?

Posts on the different types of insomnia are the next most visited category. Since the underlying causes of insomnia disorder remain unknown, insomnia is usually classified based on the symptoms people report.

Psychophysiologic (or psychophysiological) insomnia is the most common insomnia diagnosis given to those of us who report trouble sleeping at night and daytime impairments. Symptoms are both physiological (bodily tension and warmth, for example) and psychological (anxiety about sleep). Cognitive behavioral therapy (CBT) is now the first-line treatment for psychophysiologic insomnia.

A diagnosis of paradoxical insomnia may be made following a sleep study showing a large discrepancy between how much time a person reports sleeping and how much sleep is recorded on the polysomnogram (the test in the sleep lab). Treatment options vary and there’s no clear consensus on which works best.

Sleep Restriction for Insomnia Relief

Sleep restriction therapy comes in for a close third topic of interest to Savvy Insomniac readers. Offered as part of CBT-I or as a standalone therapy, sleep restriction has been found in research to improve several aspects of sleep.

Its appeal to readers of this blog may have to do with the sheer number of posts I’ve written on the topic (10) and the fact that it worked so well for me. Combined with daily exercise, sleep restriction helped me regularize my sleep and overcome my sleep anxiety. Invaluable gains, to me.

Seasonal Insomnia

Insomnia that varies seasonally is another topic that draws lots of readers. Environmental factors that occur in the spring and summer—too much light and too much heat—can easily interfere with falling and staying asleep.

Insomnia that starts in the fall and continues through the winter may be driven by other environmental factors. Lack of sunlight or other bright light is usually the culprit. Lack of vitamin D may be another factor. Expect to see an update on this topic coming fairly soon.

Don’t see a topic that interests you here? Use the contact form to ask a question about a topic that does interest you, and receive a free copy of The Savvy Insomniac.

And here’s a last request: please like and share blog posts you feel are helpful on Facebook, Twitter, and other social media. This will help The Savvy Insomniac blog remain discoverable to other insomnia sufferers looking for a better night’s rest.

Insomnia at the Approach of Summer

It happens every year in the spring: someone writes in to The Savvy Insomniac complaining of an inexplicable onset of insomnia. No stress is involved, no abrupt change in circumstances.

If you find yourself experiencing insomnia at about this time every year, the problem may have to do with lengthening days. The solution may lie in reducing your exposure to sunlight.

To conquer insomnia in the summer, reduce light exposureIt happens every year in the spring: someone writes in to The Savvy Insomniac complaining of an inexplicable onset of insomnia. No stress is involved, no abrupt change in circumstances.

Here’s how a reader described the problem this year:

 

Every year at the same time (between the end of April and the end of June, I don’t know why?), my sleep becomes very capricious. I don’t sleep when I go to bed and, inexorably, I have to start again a new ‘sleep restriction.’ I feel pretty jaded because it’s difficult!

Whenever you’re having trouble sleeping, it helps to tighten up your sleep window and stay out of the bedroom until you’re really sleepy. But if insomnia tends to strike at about this time every year, the problem may have to do with lengthening days. The solution may lie in reducing your exposure to sunlight.

Seasonal Variation in Light Exposure

The further away from the equator you live, the greater are the seasonal differences in your exposure to sunlight. Not many comparative studies have measured how these seasonal variations in day length affect people’s sleep. But one study published in 2012 compared the sleep timing and quality of people living in Norway (far from the equator) and others living in Ghana (close to the equator) in the winter and the summer.

Ghanaians rose and went to sleep at about the same time in both seasons. The Norwegians rose 32 minutes earlier (and went to bed 12 minutes earlier) in the summer than in the winter, suggesting that seasonal variation in day length can affect our internal clocks. When the days are longer and sunrise is earlier, people may tend to get up (and go to bed) a little earlier than they do in the winter.

Seasonal Affective Disorder

However, the Norwegians in this study experienced more insomnia and reported lower moods in the winter when the days were short. This finding aligns with the results of other research—from Norway, for example, and from Finland—showing that in the late fall and winter, insufficient exposure to daylight is associated with seasonal affective disorder, or SAD, and trouble sleeping.

I see anecdotal evidence of this phenomenon every year. Readers write in complaining of insomnia that typically starts in November or December. The solution to this seasonal insomnia is bright light therapy, appropriately timed.

Too Much Light?

Other people report that their insomnia typically occurs in the spring and summer. There’s a dearth of research on this phenomenon, but I suspect that excessive exposure to daylight could trigger insomnia in those who, for whatever reason, are particularly sensitive to light. Light blocks secretion of melatonin, a hormone helpful to sleep, so restricting your exposure to bright light early in the morning and later in the evening may help.

Here are suggestions for how:

  • Install light blocking curtains on bedroom windows so the morning sunlight doesn’t wake you up too early
  • Draw blinds and curtains in your home before the sun sets and keep indoor lighting low in the evening
  • Wear sunglasses if you’re outside in the sunlight very early in the morning or after about 8:30 p.m.
  • Steer clear of devices with screens in the run-up to bedtime.
  • Buy a comfortable eye mask and wear it when you sleep

If you find eye masks uncomfortable, perhaps a towel wrapped around the eyes and head will do the trick. A few years ago a neuroscientist–sleep researcher told me she was super sensitive to light at night, and this was her way of solving the problem. Do whatever works!