We know that diet and sleep are deeply connected. But the truth is, we don’t know nearly enough yet about how individual nutrients impact our sleep. Here, I look at 5 vitamins that appear to play a role in how much sleep we get and how restful and high-quality that sleep is. As you’ll see, several of these vitamins may affect our risk of sleep disorders, including insomnia and sleep apnea. And at least two of them appear to play a role in regulating our circadian rhythms, the 24-hour bio rhythms that control our sleep-wake cycles.
I’m a big believer in leveraging a healthy diet to improve sleep. Often, diet alone doesn’t give us all the nutrients we need. Supplements can play an important role in filling those gaps. (I wrote recently about 10 of the most effective supplements for sleep.)
But before you run out and add the vitamins below to your supplement list, I encourage you to do two things. Look for ways to improve your vitamin intake through your diet. And talk to your doctor. Getting the dosing—and the timing—of supplement intake is critical to success, when it comes to sleep.
Always consult your doctor before you begin taking a supplement or make any changes to your existing medication and supplement routine. This is not medical advice, but it is information you can use as a conversation-starter with your physician at your next appointment.
Many of us know Vitamin D for its role in bone health. It’s also important for regulating mood, supporting immune function, and helping to control inflammation. Vitamin D is catching a lot of interest for its potential benefits for sleep—and for the sleep consequences that accompany Vitamin D deficiencies. I’ve written before about the relationship between Vitamin D and sleep. There’s new research that is adding to our understanding of how this vitamin—and a lack of it—may affect our nightly rest.
For sleep quality and sleep quantity … There’s a growing body of research showing Vitamin D affects both how much sleep we get and how well we sleep. A recent study found Vitamin D deficiency linked to short sleep duration. This study found the links between insufficient sleep and lack of Vitamin D to be especially strong in adults age 50 and older. More than half of the people included in this study were deficient in Vitamin D. That aligns with other research that shows a majority of Americans may be lacking in Vitamin D. In 2018, scientists at China’s Qingdao University analyzed the findings of several studies that looked at Vitamin D’s role in sleep. Their analysis identified significant connections between low levels of Vitamin D and a lack of sleep. They also found low levels of Vitamin D were connected to poor sleep quality.
For sleep apnea … Several recent studies have shown a connection between Vitamin D deficiency and risk of sleep apnea. A lack of Vitamin D may also affect the severity of sleep apnea, with lower D levels linked to more severe cases of OSA in several recent studies. Some good news on the sleep apnea front: research investigating the standard treatment for sleep apnea—CPAP, or continuous, positive airway pressure—has found that long-term CPAP use is connected to a significant increase in Vitamin D levels, along with significant improvements to sleep apnea symptoms.
For bio-clock timing: Vitamin D may influence sleep at least in part by helping to regulate our circadian clocks. That’s the takeaway from some recent research, which shows that Vitamin D may activate two circadian clock genes, which in turn control our 24-hour circadian rhythms. Light and darkness, we know, are the primary regulators of our internal bio clocks. Sunlight is also our single best source of Vitamin D. It looks as though Vitamin D may be a part of the mechanism by which sunlight keep our bio clocks—and our daily sleep cycles—running in sync.
Where to find Vitamin D in your diet … Sunlight, not diet, is the number one source of Vitamin D. The body produces its own Vitamin D, in response to exposure to sunlight. For this reason, Vitamin D isn’t actually considered a vitamin at all, but rather is classified as a hormone. Beyond sun exposure, people also receive Vitamin D through foods—fatty fish and fish oils, egg yolks, as well as fortified foods like dairy and juice.
A powerful antioxidant, Vitamin E helps maintain healthy cell function and protect cells from damage. It also supports immune health. Vitamin E’s antioxidant capabilities may also help sleep and sleep-related health problems.
For sleep-related memory protection…. One effect of sleep deprivation is trouble with memory. During sleep, including both slow-wave sleep and REM sleep, the brain processes memories and our newly acquired learning. When we’re short on sleep, we can encounter problems with both short and long-term memory recall. Thanks to its antioxidant capabilities, Vitamin E offers protection for the health and function of the brain. And research indicates this vitamin might offer specific protection against the memory impairment from sleep loss. A 2012 study found that Vitamin E reduced memory loss in sleep-deprived rats. Vitamin E appears to work by protecting the function of the hippocampus, an area of the brain that is critical to memory consolidation. Research has shown sleep deprivation is highly disruptive to activity of the hippocampus.
For sleep apnea…People with sleep apnea often have low levels of Vitamin E. Elevating levels of this vitamin may help to improve Studies have shown that Vitamin E, in combination with Vitamin C and other antioxidants, can improve nighttime breathing and sleep quality in people with obstructive sleep apnea.
For sleep-related hormone protection…. Maintaining healthy levels of Vitamin E may protect testosterone production from the effects of sleep deprivation. A lack of sleep has been linked to lower testosterone levels.
Where to find Vitamin E in your diet…Foods containing higher amounts of Vitamin E include many nuts and seeds, including almonds, peanuts, hazelnuts and sunflower seeds, as well as spinach, broccoli, tomatoes, wheat germ oil, corn and soybean oils.
Another antioxidant powerhouse, C is the vitamin many of us associate most strongly with immune health. It’s also important for cardiovascular health, and necessary for the body to make collagen, which is critical for healthy bones, teeth and skin. Vitamin C’s health-promoting abilities may also extend to sleep.
For sleep apnea and related health risks… On its own and in combination with other antioxidants, Vitamin C has been shown to improve the symptoms of obstructive sleep apnea. This 2009 study showed that a combination of Vitamin C (100 mg) and Vitamin E (400 IU) taken twice daily reduced episodes of apnea, the interrupted breathing that is the hallmark symptom of OSA. This C and E combination also improved sleep quality and decreased daytime sleepiness.
One of the major risks linked to sleep apnea is cardiovascular disease. People with untreated OSA are more likely to have high blood pressure, metabolic problems including obesity, arrhythmias and other cardiovascular issues. OSA is linked to problems with the lining of blood vessels (what’s known as the endothelial lining), which helps maintain healthy circulation. Research indicates that Vitamin C may improve endothelial function in people with OSA, potentially relieving some of the stress that this sleep disorder puts on the cardiovascular system.
To increase sleep amounts and sleep quality… Low intake of Vitamin C has been connected to shorter sleep amounts. This 2013 study by scientists at the University of Pennsylvania found that short sleepers—people who slept less than 6 hours a night—consumed less Vitamin C than people who consumed more of the vitamin. Lower levels of Vitamin C as measured in blood were also linked to more nightly sleep disturbance and a greater risk for sleep disorders.
For memory protection… Similar to vitamin E, Vitamin C has been shown to offer protection for the brain against the memory losses associated with sleep deprivation.
Where to find Vitamin C in your diet… Citrus fruits are rich sources of Vitamin C, as are broccoli, cauliflower, brussels sprouts, kale, spinach, green and red chilis, strawberries, and kiwi.
Vitamin B6 is involved in many functions in the body. It supports immune health, and aids in cognitive development and function. There’s evidence that B6 also aids sleep—and affects our dreams.
For dream recall… I wrote recently about lucid dreams, a form of dreaming in which the sleeper has awareness of being in a dream, and in some cases can control the action of their dreams. There’s always a lot of interest in lucid dreams—people are particularly interested in finding ways to induce lucid dreaming. (You can read my latest on lucid dreaming, here.) A 2018 study at Australia’s University of Adelaide found that Vitamin B6 may help people increase their ability to remember their dreams. People with stronger dream recall are more likely to have lucid dream experiences.
For melatonin and serotonin production… A lack of Vitamin B6 has been linked to symptoms of insomnia and depression. Vitamin B6 aids in the production of the hormones serotonin and melatonin, both of which are important to sound, restful sleep, and also to mood. There’s a strong correlation between depression and sleep problems. Among people with depression, 75 percent or more also have symptoms of insomnia. (Not everyone with depression experiences insomnia or short sleep. A smaller number of people sleep excessively, a disorder known as hypersomnia. Hypersomnia is particularly common in teenagers and young adults with depression.) In studies of older adults, higher intake of Vitamin B6 been connected to lower risk for depression.
Where to find Vitamin B6 in your diet … Bananas, carrots, spinach, potatoes are great sources of B6, as are milk, eggs, cheese, fish, and whole grains.
A NOTE ABOUT VITAMIN B6: It’s always important to talk about your supplement use with your doctor. That’s especially true for Vitamin B6. High levels of Vitamin B6 can be toxic. And excessive levels of B6 have also been linked to insomnia. If you’re considering a B6 supplement, it’s important to work with your doctor to find the right dose.
Vitamin B12 is important for brain function, supporting cardiovascular health including red blood cell formation, and in supporting DNA activity. Here’s what we know about its effects on sleep.
As a sleep-wake regulator… The role of Vitamin B12 is interesting. Several studies have demonstrated that this vitamin is involved in regulating sleep-wake cycles by helping to keep circadian rhythms in sync. At the same time, the influence of B12 directly on sleep isn’t clear. Some studies show a connection between low Vitamin B12 and insomnia, while other studies show higher levels of Vitamin B12 are linked to sleep disruption and shorter sleep times. (The mixed results of Vitamin B12 are a prime example of why we need a lot more scientific attention paid to ways nutrients affect sleep!)
Higher levels of Vitamin B12 have been connected to a lower risk of depression. Circadian rhythm disruptions are a significant underlying factor for depression. In addition to other issues with sleep, with depression are often unable to sleep on a routine schedule. It may be that Vitamin B12 is specifically useful for people with sleep-wake disruptions, including in people who also have symptoms of depression. But we need more research to better understand how Vitamin B12 influences sleep.
Where to find Vitamin B12 in your diet … Vitamin B12 is found in animal protein dietary sources, including dairy, eggs, meat, fish and shellfish.
The closer we stick to a diet of diverse, whole, unprocessed foods, the more of these vitamins we’ll pick up naturally. (And don’t forget to get out in the sun for your vitamin D fix!) These are some of the simplest, most important sleep habits we can adopt.
Michael J. Breus, PhD, DABSM
The Sleep Doctor