Magnesium and Sleep in babies and toddlers: what does the science say?

Magnesium is all over social media. It even seems to be eclipsing melatonin as the "natural" supplement of choice for sleep. You've probably seen posts claiming that some magnesium-containing product is the secret to getting your baby or toddler to sleep through the night. From topical magnesium creams to apply during your bedtime routine to oral drops and supplements, these products are often marketed as natural, gentle solutions for little ones who struggle with sleep. Before you consider buying magnesium for your child, it's worth taking a closer look at what the research actually says.

The Science

Magnesium is a mineral that the human body uses as a resource for many cellular functions. Some scientists speculate that magnesium could be a factor that promotes sleep because it activates gamma-aminobutyric acid (GABA) by binding to its receptors. GABA is a primary sleep-inducing neurotransmitter (though the neurobiology of sleep is incredibly complex and much more than just GABA activation is involved!).

Where does your body get magnesium?

Your body gets magnesium from your diet. It's part of chlorophyll, so most leafy green vegetables contain a lot of magnesium. It's also found in whole grains, beans, nuts like almonds, seeds such as pumpkin seeds, and even dark chocolate. Your body stores it in your bones, muscles, and tissues so that you have it available when you need it.

Oral magnesium supplements are often used to make up for deficits in nutritional magnesium consumption, but there are many different forms of magnesium available. Magnesium oxide (MgO) is a common form of magnesium supplement, but several supplements contain magnesium bound to amino acids (chelates). Magnesium oxide has historically been used as a laxative, and people who use magnesium supplements sometimes complain of experiencing diarrhea.

Transdermal (through the skin) magnesium preparations also vary considerably, with different forms of magnesium and different applications such as creams, sprays, and salt baths. Most studies did not find much difference in magnesium levels following use, and several found that the preparation of magnesium used was not absorbed by the body. This led one review paper to conclude that using magnesium creams, sprays, and salts is currently "scientifically unsupported."

What can studies in adults tell us about magnesium and sleep?

There haven't been many studies examining the relationship between magnesium and sleep in adults. The existing studies vary in the type, dosing, timing, and duration of magnesium supplementation, with some participants being elderly or having other chronic conditions like depression or fibromyalgia. Most of the magnesium studies used questionnaires to determine how participants slept. Perhaps not surprisingly given these differences, the studies show mixed results.

For example, a recent epidemiological evaluation compared magnesium intake (either dietary or supplements) to sleep duration and quality over 20 years. Researchers found that the quarter of the population with the highest magnesium intake had marginally better sleep quality and reduced likelihood of sleeping less than seven hours compared with the quarter of the population with the lowest intake. This was a strong study design that followed people over many years, but the benefits of magnesium were weak at best.

What do you need to know about magnesium in young children?

Magnesium is able to pass to babies through breast milk. The amount present in breast milk varies based on a wide range of factors (e.g., mother's diet, smoking status, age, etc.). A study from 1970 found that formula-fed babies had lower magnesium concentrations compared to breastfed babies, but formula has changed significantly since 1970, so it's difficult to interpret that finding in the context of modern parenting.

Research on magnesium and sleep in babies and toddlers is extremely limited. There are no studies that we could find suggesting that medically typical children experience magnesium deficiency. We also couldn't find any research on popular forms of magnesium supplementation marketed for babies and toddlers, such as oral drops, topical creams, or sprays.

One study published in 1980 found that among 14 full-term babies, those with higher circulating magnesium levels had more quiet sleep. (Newborns have two stages of sleep: active and quiet sleep; we cover this in our 0-6 month sleep class and four-month regression blog.) When the babies received magnesium injections (yikes, can't believe they subjected babies to this), they had more quiet sleep. However, it is difficult to interpret this because having more quiet sleep doesn't necessarily mean better quality sleep.

Another study assessed sleep in premature babies whose mothers were given magnesium sulfate, steroids, a combination of the two, or nothing during pregnancy. That study also found changes in the distribution of active and quiet sleep among babies whose mothers received magnesium supplements compared to those who didn't. However, only five mothers out of 134 received the magnesium supplementation alone (45 received magnesium and steroids), making these results difficult to interpret.

Is magnesium supplementation safe?

Due to the limited studies in babies and young children, it's hard to know if there are any concerning side effects associated with magnesium supplementation. Some studies in adults suggest that diarrhea is the most common adverse event that occurs, but reports on people who have accidentally consumed excessive amounts of magnesium through near-drowning in the Dead Sea suggest that it damages the electrolyte balance in the body, causing lung damage and cardiovascular issues.

The Bottom Line

Based on these very limited studies, we do not recommend magnesium supplementation for babies or young children. If you are concerned that your baby may have a magnesium deficiency, talk with your pediatrician about your concerns. Your pediatrician will be able to tell you if magnesium supplementation is an appropriate treatment. Remember, just because a supplement is for sale doesn't mean it has been appropriately tested for safety or benefits.

Need more help?

We are moms with formal education in sleep medicine, nursing, and behavior analysis. If you are struggling with sleep, check out our many free blogs on how to solve common problems. We have blogs on naps, schedules, travel, toddler issues, and more! We also offer comprehensive self-paced classes with expert support in a private chat on Instagram (0-6 month class, and sleep training class).

If you just need to talk to someone who can help you devise a sleep plan, then feel free to book a one-on-one consultation with us. We are always happy to help!

References:

Zhang, Y., Chen, C., Lu, L., Knutson, K.L., Carnethon, M.R., Fly, A.D., Luo, J., Haas, D.M., Shikany, J.M. and Kahe, K., 2022. Association of magnesium intake with sleep duration and sleep quality: findings from the CARDIA study. Sleep, 45(4), p.zsab276.

Rawji, A., Peltier, M.R., Mourtzanakis, K., Awan, S., Rana, J., Pothen, N.J., Afzal, S. and Pothen, N., 2024. Examining the effects of supplemental magnesium on self-reported anxiety and sleep quality: a systematic review. Cureus, 16(4).

Arab, A., Rafie, N., Amani, R. and Shirani, F., 2023. The role of magnesium in sleep health: a systematic review of available literature. Biological trace element research, 201(1), pp.121-128.

Gröber, U., Werner, T., Vormann, J. and Kisters, K., 2017. Myth or reality—transdermal magnesium?. Nutrients, 9(8), p.813.

Elgar, K., 2022. Magnesium: a review of clinical use and efficacy. cell, 2, p.3.

Dralle, D. and Bödeker, R.H., 1980. Serum magnesium level and sleep behavior of newborn infants. European journal of pediatrics, 134(3), pp.239-243.

Dórea, J.G., 2000. Magnesium in human milk. Journal of the American College of Nutrition, 19(2), pp.210-219.

Harvey, D.R., Cooper, L.V. and Stevens, J.F., 1970. Plasma calcium and magnesium in newborn babies. Archives of Disease in Childhood, 45(242), pp.506-509.