Updated: Nov 24
Scientists don’t know exactly why we sleep, but they have discovered that some essential functions occur while asleep. Quality sleep is crucial for primary restorative processes, like muscle growth, tissue repair, protein synthesis, and growth hormone release. Let's learn which nutrients promote it.
As someone who struggled with sleep since I was a pre-teen, it’s easy to think you’ll never get a restful sleep, especially if you haven’t had one in a long time. I’m here to tell you that this doesn’t have to be the case, and you don’t need a prescription to get the job done. You don’t need melatonin, either!
Let’s start with the basics: why is sleep important? The truth is that scientists don’t exactly know why we sleep, but they have discovered that some of the most essential functions occur while we are asleep. For instance, primary restorative processes, like muscle growth, tissue repair, protein synthesis, and growth hormone release, occur when the body rests (1).
So, how much sleep is considered optimal? The National Sleep Foundation recommends the following sleep duration guidelines (2):
Newborns (0-3 months): 14-17 hours per day
Infants (4-11 months): 12-15 hours per day
Toddlers (1-2 years): 11-14 hours per day
Preschooler (3-5 years): 10-13 hours per day
School-aged (6-13 years): 9-11 hours per day
Teens (14-17 years): 8-10 hours per day
Young Adults (18-25 years): 7-9 hours per day
Adults (26-64 years): 7-9 hours per day
Older Adults (65+ years): 7-8 hours per day
So, how do we make these numbers possible? Although there are many variables to getting adequate sleep, proper nutritional intake is my first recommendation.
Before we dive into nutrients that promote quality sleep, I’d like to recommend an educational resource from Earthley Wellness – The Secret to a Good Night’s Sleep. This is a guide that I co-wrote and designed highlighting the link between key nutrients, lifestyle choices, and sleep. It focuses on making healthy changes and balancing these nutrients to naturally improve your sleep – all based on scientific research.
Now, for the moment, you’ve been waiting for – 5 nutrients to promote quality sleep.
Iron is an essential mineral that helps transport oxygen throughout the body. Iron is a crucial component of hemoglobin, the substance in red blood cells that carries oxygen from your lungs throughout your body (3). An iron deficiency can be identified by feeling cold, brittle nails and hair thinning. Studies have demonstrated that adults with low iron levels have poorer sleep quality (4). Poor sleep quality can lead to commonly experienced restless legs, leading to relaxation aversion and disturbed sleep (5,6). Thankfully, getting more iron can improve restless leg symptoms (7).
Studies have pinpointed a distinctive gene associated with insomnia and anemia arising from iron deficiency (8). Women have a heightened risk of insomnia compared to men, making women more prone to iron-deficient anemia than men. It’s also no surprise that iron and vitamin D (which we will discuss later) significantly correlate with sleep quality, quantity, timing, and modulation of REM sleep (9).
Natural sources of iron include (10):
Meat and fish (beef, oyster, turkey)
Legumes (lentils, green peas, chickpeas)
Nuts (cashews, peanuts)
Vegetables (spinach, potatoes, tomatoes)
Grains (brown rice, white rice, whole wheat)
I don’t supplement iron, but my husband does with Earthley’s Energy Plus.
If you read my blog, The Importance of Magnesium, you know it's the fourth most abundant mineral in the body and participates in over 300 different functions. Magnesium is an electrolyte (metal salt/ion) that helps muscles work effectively, produces a calming effect, keeps bowels moving, regulates temperature, and more (11).
Many of us are deficient in magnesium, and numerous factors can contribute to a person becoming deficient. Low magnesium levels are why people often struggle to fall asleep and stay asleep, causing a night of restless sleep and frequent awakening. Magnesium supports deep restorative sleep by maintaining healthy levels of GABA.
Some studies have shown that magnesium has a beneficial impact on sleep (12). It may also improve restless leg symptoms (although iron was more effective) (13). Although the science is mixed on the benefits of magnesium for restless leg symptoms, many people claim that it has helped them significantly – and it’s known for calming muscles.
Natural sources of magnesium include (14):
Seeds (pumpkin, chia)
Nuts (almonds, cashews)
Vegetables (spinach, broccoli)
Fruits (apples, bananas)
Beans (kidney, black)
Meat (chicken, salmon)
You can always supplement magnesium, but not all supplements are created equally. When taken orally, magnesium can cause stomach upset and diarrhea, which most people (myself included) prefer to avoid! My go-to way magnesium is Earthley’s Good Night Lotion.
Fats, in moderation, are an essential part of a healthy, balanced diet. Fats are a source of essential fatty acids, meaning the body cannot make them. For instance, omega-3 fatty acids contain alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). These fats help the body absorb vitamins A, D, and E. These vitamins are fat-soluble, meaning they can only be absorbed with the help of fats (15).
Most commonly, omega-3s are known for their heart and bone health benefits and their cognitive and cancer-protecting benefits. Additionally, growing bodies of research indicate that diets rich in omega-3s correlate with better sleep quality in adults and children.
One study found that higher blood levels of omega-3s were significantly associated with better sleep quality, including decreased bedtime resistance, sleep disturbance, and parasomnias (16). Another study concluded that omega-3s benefit sleep, including increased sleep efficiency and reduced sleep latency (17).
Natural sources of omega-3s include (18):
Seafood (salmon, mackerel, tuna, herring, sardines)
Seeds (flaxseed, chia seeds)
Plant oils (flaxseed, avocado)
Most people don’t need to supplement omegas unless they’re plant-based. In that case, I’d recommend Garden of Life’s Vegan DHA. For those who aren’t plant-based but are still looking to supplement omegas, Earthley’s Cod Oil is an excellent option.
Believe it or not, vitamin D is not a vitamin but a pre-hormone. This pre-hormone uses chemical messengers to help the body make all the other hormones it needs, which impacts sleep. This nutrient helps our body absorb and retain calcium and phosphorus, both vital for building bone. Like omega-3s, vitamin D is a fat-soluble nutrient, but our bodies can produce it, so it’s non-essential but still important to get enough.
Studies indicate that low vitamin D levels are correlated with worse sleep and an increased risk of sleep disorders (19). One study discovered vitamin D levels under 20 ng/ml were associated with poor sleep and daytime sleepiness (20). Studies have even demonstrated vitamin D can diminish cancer cell growth, help battle infections, and reduce inflammation (21). Unfortunately, many people are deficient in vitamin D. A 2009 study showed that 42% of teens and adults had a level under 30 mg/ml (22).
While the sun is the best source of vitamin D (23), it is also found in a few foods, like cod liver oil and certain mushrooms. Mushrooms grown in sunlight contain about 450 IU per 100-gram serving (24). The best mushrooms for vitamin D are portobello, maitake, morel, button, and shiitake. When the sun is unavailable, topical vitamin D can be beneficial (25,26).
Zinc is another significant mineral that plays a crucial role in sleep metabolism. Some studies have found that optimal zinc levels predict the best sleep schedule (not too much or too little) (27). Zinc is also responsible for gene expression, enzymatic reactions, immune function, protein synthesis, DNA synthesis, wound healing, growth and development, and more.
While zinc is influential in many biological processes, it’s been recognized for its role in functions such as memory and sleep. Evidence has found zinc to be a sleep modulator (28). One study found preschool kids (ages 3-5) with low zinc levels had poor sleep in adolescence years (ages 11-15) (29).
Although zinc doesn’t trigger sleep, adequate zinc blood levels reduce the time it takes to fall asleep. Reduced sleep latency influences increased sleep and improved sleep quality.
Natural sources of zinc include (30):
Meat and fish
Seeds (hemp, pumpkin, chia, flax)
Mushrooms (shiitake, white button)
Beans and lentils (black, lima)
Wild rice and quinoa
Since zinc is widely available in whole foods, most people don’t need a supplement. I take zinc because I have an autoimmune disease. Earthley’s Oyster-Min Capsules are an excellent zinc supplement for those who aren’t plant-based. For those who are plant-based, I have used MaryRuth’s Liquid Ionic Zinc in the past but switched to Garden of Life’s Raw Zinc Capsules as it was the most cost-effective.
⚠️ Warning: The Holistic Hipppie is not a functional medicine practitioner. The FDA has not evaluated these statements. This content is not medical advice and should not be used to diagnose, treat, cure, or replace medical guidance. The Holistic Hipppie assumes no liability for the application of the information discussed.