Vitamin D
Many of us know vitamin D for its role in bone health. It’s also generating a lot of interest for its potential benefits for sleep and for the sleep consequences that accompany vitamin D deficiencies. There’s new research that is adding to our understanding of how this vitamin — and a lack of it — may affect our nightly rest.
Sleep Quality and Quantity
There’s a growing body of research showing vitamin D affects both how much sleep we get and how well we sleep.
One found vitamin D deficiency linked to short sleep duration, especially for adults age 50 and older. And more than half of the people included in this study were deficient in vitamin D, a finding consistent with estimates in the general U.S. adult population.
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, as well as poor sleep quality.
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 obstructive sleep apnea (the most common type of sleep apnea) in several recent studies.
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.
Bio-Clock Timing
Vitamin D may influence sleep at least in part by helping to regulate our circadian clocks. Light and darkness, 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.
How to Get More Vitamin D
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. People also get vitamin D from foods like fatty fish and fish oil, egg yolks, and fortified foods like dairy and juice.
Vitamin E
A powerful antioxidant, vitamin E helps maintain healthy cell function and protect cells from damage. It may also contribute to healthier sleep.
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's critical to memory consolidation. Research has shown sleep deprivation is highly disruptive to activity of the hippocampus.
Sleep Apnea
People with sleep apnea often have low levels of vitamin E. 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.
Sleep-Related Hormone Production
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.
How to Get More Vitamin E
Foods containing higher amounts of vitamin E include many nuts and seeds, as well as spinach, broccoli, tomatoes, wheat germ oil, corn, and soybean oil. Vitamin E’s antioxidant capabilities may also help sleep and sleep-related health problems.
Vitamin C
Another antioxidant powerhouse, vitamin 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.
Sleep Apnea
On its own and in combination with other antioxidants, vitamin C has been shown to improve sleep apnea symptoms. A 2009 study showed that a combination of vitamin C (100 mg) and vitamin E (400 IU) taken twice daily reduced episodes of apnea, and also improved sleep quality and decreased daytime sleepiness.
Some 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.
Sleep Quality and Quantity
Low intake of vitamin C has been connected to shorter sleep amounts. A 2013 University of Pennsylvania study found that people who slept less than six 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.
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.
How to Get More Vitamin C
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
Vitamin B6 is involved in many functions in the body. It supports immune health and cognitive development and function. There’s evidence that B6 also aids sleep and affects our dreams.
Dream Recall
There’s always a lot of interest in lucid dreams—people are particularly interested in finding ways to induce lucid dreaming. 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.
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. Among people with depression, 75% or more also have symptoms of insomnia.
Not everyone with depression experiences insomnia. A smaller number of people sleep excessively, a disorder known as hypersomnia. Hypersomnia is particularly common in teenagers and young adults with depression.
How to Get More Vitamin B6
Bananas, carrots, spinach, and potatoes are great sources of B6, as are milk, eggs, cheese, fish, and whole grains.
If you’re considering a B6 supplement, it’s important to work with your doctor to find the right dose. Excessive levels of vitamin B6 can be toxic and has also been linked to insomnia.
Vitamin B12
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.
Sleep-Wake Regulation
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. Higher levels of vitamin B12 have been connected to a lower risk of depression. Circadian rhythm disruptions are a significant underlying factor for depression. 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.
How to Get More Vitamin B12
Vitamin B12 is found in animal protein dietary sources, including dairy, eggs, meat, fish and shellfish.
