Like so many other topics, the research consensus about sleep nutrients and vitamins is boring. There is no magic pill that condenses eight hours of quality sleep into five, that puts you to sleep instantly and keeps you asleep all night. Per the research, the answer to how to improve sleep with nutrition appears to be eating a variety of nutrient-rich foods. While other factors, like light, sound, and temperature, play a role in sleep quality and duration, consuming recommended amounts of these nine nutrients throughout the day can support healthy sleep.
In various studies, low vitamin D has been associated with short sleep, difficulty maintaining sleep, non-restorative sleep, and even sleep apnea and other sleep disorders. Scientists have identified Vitamin D receptors in areas of the brain that regulate sleep and other research suggests potential vitamin D involvement in decreasing inflammatory substances which also affect sleep.
Vitamin D is one of the more common nutrient deficiencies in the United States. Few foods aside from fatty fish naturally contain this critical sleep nutrient, so fortified foods like milk are primary sources in diet. Most Vitamin D comes from sun exposure, which also plays a role in circadian rhythm, thus sleep.
This antioxidant — which is responsible for the red and pink pigment of tomatoes, red grapefruit, and watermelons — is associated with less difficulty falling asleep. Low lycopene consumption has also been noted among people with short sleep duration.
Deficiency of this mineral has been linked to shorter sleep duration. In a recent study, subjects fell asleep faster and had more efficient sleep after eating zinc-rich foods. In another, subjects administered a supplement containing zinc, magnesium, and melatonin experienced improved sleep quality and sleep time.
Older adults, people with gastrointestinal disorders, and vegans are more susceptible to zinc deficiency due to low consumption of bioavailable zinc from animal sources and/or absorption difficulties.
Research indicates an association between short sleep duration and magnesium deficiency. In a recent study, elderly subjects who received 500mg magnesium experienced longer, more restorative sleep along with higher melatonin levels and lower concentration of stress hormone cortisol. Magnesium helps perform hundreds of essential functions in the body, among them acting as a clock in cells and supporting sleep regulators.
Magnesium deficiency is difficult to assess, but some researchers estimate it to be high among the United States population due to declining magnesium content in plants. Magnesium is a common supplement in various forms with Magnesium Citrate, Magnesium Glycinate, and Magnesium L-Threonate among the better used in the body as a sleep nutrient and more.
Multiple studies indicate this essential amino acid supports better sleep quality. Subjects following a tryptophan-rich diet were more alert and less sleepy the following morning than those given a placebo. In a study on athletes, subjects who ate tryptophan-rich protein in the evenings experienced better quality sleep. Researchers suggest the high tryptophan content of foods like tart cherry juice, milk, and oily fish may be responsible for their demonstrated beneficial effects on sleep.
As an essential amino acid, your body cannot produce tryptophan, so it’s necessary to consume this sleep nutrient through diet or complete protein supplements.
In multiple studies, researchers have found correlation between low Vitamin C — as well as low intake of Vitamin C-containing fruits and vegetables — and short, non-restorative sleep. Smoking, which depletes antioxidants like Vitamin C, has a similar effect.
Vitamin C is one of the most commonly supplemented nutrients, but effectiveness varies significantly by type with many Vitamin C supplements absorbing only at low levels.
Vitamin A deficiency is rare in the United States as this sleep vitamin is found in a variety of foods, including leafy greens, eggs, milk, and tomatoes.
In studies, low calcium is associated with difficulty falling asleep and non-restorative sleep. With fellow electrolytes magnesium and potassium, calcium appears to play a role in the sleep/wake cycle and support sleep hormone melatonin production.
Calcium deficiency is common, particularly in older women and people who avoid dairy products, one of the primary sources along with leafy greens and fatty fish. In supplements, calcium is frequently paired with fellow sleep nutrient Vitamin D to enhance absorption.
Nutrients for sleep come from a diverse diet
Overall, people who report eating the greatest variety of food had optimal sleep duration. Those with restrictive diets were more likely to either sleep too little or too much, both of which are implicated in negative health outcomes. Other nutrient deficiencies linked with suboptimal sleep include phosphorous, B1 (thiamine), iron, and folate.
In other research, people who consumed the fewest macronutrients (proteins, carbs, fats, fiber), were more likely to report short sleep. Failure to consume enough food can mean failure to consume enough nutrients for sleep. Conversely, the group in another study that reported eating the most macronutrients (except fiber) also reported short sleep.
The bottom line is that nutrients for sleep is a snooze-inducing topic. The research suggests eating the right amount of a wide variety of nutrient-rich foods and drinking plain water is how to improve sleep.