You already know that things like stress and the blue light from screens can leave you staring at the ceiling wide awake come bedtime. But you might not realize how much what you eat—and don’t eat—affects your ability to drift off. Not only does your diet influence your shut-eye, but certain nutritional deficiencies can make quality rest darn near impossible.
That’s why when sleep specialist Michael Breus, PhD, starts seeing a patient with sleep issues, he runs blood work to test their nutrient levels and often refers them to a dietitian. “Sleep is a holistic process,” he says, and proper nutrition is a key part of that process.
Here, six vitamin and mineral deficiencies to look out for—and how to increase your intake for better sleep.
Vitamin D
Perhaps best known for its role in immune function, bone health, and hormone production, vitamin D also has a major impact on sleep.
According to Breus, vitamin D helps regulate your circadian rhythm, the “internal clock” that helps you wake up in the morning, feel energized throughout the day, and fall asleep at night. (This makes sense, since your primary source of vitamin D is the sun, and light and dark both have significant influence on your circadian rhythm.)
Research suggests that without ample vitamin D, your sleep suffers. One 2014 survey published in the Journal of Sleep Research, for example, linked low vitamin D to difficulty staying asleep at night. Meanwhile, a 2018 meta-analysis published in Nutrients identified a link between low vitamin D levels and shorter sleep duration, poor sleep quality, and risk of sleep disorders such as sleep apnea.
Considering that a 2008 study in the Journal of the American College of Cardiology suggests up to 50% of Americans may be vitamin D deficient, it’s one of the first nutrients to look into if you’re having trouble sleeping.
Magnesium
Currently trending in the supplement world, the mineral magnesium is beloved for its ability to help your mind and body relax.
Often referred to as the “sleep mineral,” magnesium “helps activate neurotransmitters responsible for calming our body and mind, not only helping us sleep but helping us achieve deep and restful sleep,” explains dietitian Jenna Appel, RDN. Research suggests it does so specifically by supporting the release of melatonin.
“Unfortunately, though, because much of our farming soil has been over-tilled, much of our food no longer provides the magnesium we need,” says Breus. Given this, some studies suggest that most people are at risk for magnesium deficiency.
According to a 2012 review published in Nutrition Research, magnesium supplementation has been shown to improve both sleep quality and sleep duration in people with low magnesium and people with sleep issues.
Related: The right foods to eat for better sleep
Vitamin B6
B vitamins, which help your body break food down into usable nutrients and help you feel energized, also play a role in regulating rapid eye movement sleep, your deepest stage of sleep.
According to family doctor Nikola Djordjevic, MD, vitamin B6, in particular, affects your sleep because your body needs it to convert the amino acid tryptophan into serotonin, a “feel-good chemical” that helps regulate your levels of the sleep hormone melatonin.
A study published in Nutrition Research and Practice even associated low B6 levels with insomnia. It also linked low levels with depression, which often goes hand-in-hand with sleep issues, says Djordjevic.
Vitamin B12
Like vitamin B6, low vitamin B12 is also linked with depression and sleep issues.
Though we still have lots to learn about the specific role B12 plays in affecting sleep, some limited research does suggest its involvement in your sleep-wake cycle. This research found that B12 supplementation helped regulate the sleep-wake cycles of two patients who had long lived with sleep-wake cycle disorders.
Related: 6 late-night snacks that will help you sleep
Iron
The mineral iron, which helps transport oxygen throughout your body, may be implicated in one particularly frustrating sleep-disruptor: restless legs syndrome (RLS).
According to Arielle Levitan, MD, author of The Vitamin Solution, low iron is a significant contributor to the neurological condition, which typically involves uncomfortable sensations in the lower body that keep many sufferers up at night. (The National Sleep Foundation estimates that one in 10 adults may have RLS.)
Johns Hopkins Medicine identifies iron insufficiency as “the single most consistent finding and the strongest environmental risk factor associated with RLS.”
RLS aside, research suggests having iron deficiency anemia (a condition in which iron deficiency affects the number of healthy red blood cells in your bloodstream) may have a general impact on sleep, with one African Health Sciences study finding that anemic participants reported poorer sleep quality.
Zinc
Though not traditionally thought of as a sleep regulator, zinc, the second most abundant mineral in your body, may, in fact, influence your Z’s, says recent research.
One study published in Biological Trace Element Research, for example, found that women with the highest blood and hair levels of the mineral reported sleeping for longer. A large study on Chinese children published in Nutrients also connected zinc levels with sleep quality and disturbances, warranting further study into how this key mineral interacts with the body processes that affect your ability to rest at night.
How to address nutrient deficiencies—and get your sleep back on track
If you suspect a nutritional deficiency may be the culprit behind your crummy shuteye, Breus recommends upping your intake of these sleep-supporting vitamins and minerals through your diet or supplements.
Here are the recommended daily allowances for the vitamins and minerals outlined in this article:
- Vitamin D: 600 IU (international units) for adults up to age 70; 800 IU for adults over age 70
- Magnesium: 400-420 mg for adult men, depending on age; 310-320 mg for adult women, depending on age
- Vitamin B6: 1.3-1.7 mg for adult men, depending on age; 1.3-1.5 mg for adult women, depending on age
- Vitamin B12: 2.4 mcg (micrograms) for adults
- Iron: 8 mg for adult males; 18 mg for adult women up to age 50; 8 mg for adult women over age 50
- Zinc: 11 mg for adult men; 8 mg for adult women
“The good thing about supplements is that you can try them and if they help, great,” says Breus, who suggests supplementing with the recommended daily value of a given vitamin or mineral for 30 to 60 days and gauging how you feel.
If upping your intake of these nutrients doesn’t help you score better quality sleep, it’s time to pay a visit to your doc. They can test you for any deficiencies, refer you to a dietitian, and address any other underlying issues standing between you and a good night’s sleep.
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