What form of magnesium is best for kids? What do naturopathic doctors use magnesium for?

Why is magnesium so important for children?

Magnesium is an important mineral that serves as a cofactor for more than 300 enzymatic reactions in the body.¹ Magnesium contributes to hundreds of ATP-requiring processes involved in metabolism, energy production, oxidative phosphorylation, and glycolysis. Magnesium is required to break down carbs and fat to turn them into energy. It’s required for protein synthesis, cell replication, DNA and RNA synthesis. Magnesium facilitates neural impulses that control muscle contraction and normal heart rhythms.² It plays a role in blood glucose control, blood pressure regulation, and is a critical component of bones and teeth.¹ Most magnesium is found in bone, muscle, and inside cells, making it difficult to assess its status.¹

Recommended Dietary Allowances (RDA) for Magnesium:

The RDA for newborns until 12 months is based on the average intake of magnesium in breastfed infants.² The RDA is adjusted at 7 months to account for the addition of solid foods. The RDA for magnesium is as follows:

Absorption and food sources of Magnesium:

The absorption of magnesium from the digestive tract varies depending on several factors, including the overall magnesium status of the individual and the source of magnesium. Typically, the body absorbs about 30% to 40% of the dietary magnesium consumed, although this can vary. Magnesium is more efficiently absorbed when intake is low. Its absorption is enhanced by vitamin D and inhibited by calcium.

Magnesium in plant-based foods is bound to phytates and other antinutrients, which can reduce its bioavailability. Soaking, sprouting, and fermenting grains and legumes can improve magnesium absorption by reducing these antinutrients. High fiber can also bind magnesium, leading to lower absorption of magnesium. (Note, dietary fiber in general is almost always helpful for the general health of the gastrointestinal system, and I would not recommend a low-fiber diet in order to raise magnesium levels.) The health of the gastrointestinal tract also plays a crucial role in magnesium absorption. Conditions that affect the intestine, such as Crohn’s disease or celiac disease, can lead to reduced absorption.

Magnesium is widely available in various foods, particularly in:

1. Green Leafy Vegetables: Such as spinach and Swiss chard, which are among the best sources of magnesium.
2. Nuts and Seeds: Almonds, sunflower seeds, Brazil nuts, cashews, chia seeds, and flaxseeds are excellent sources.
3. Legumes: Beans, lentils, chickpeas, and peas are rich in magnesium.
4. Whole Grains: Such as brown rice, quinoa, whole wheat, and oats contain good amounts of magnesium.
5. Fish: Especially fatty fish like salmon, mackerel, and halibut.
6. Bananas: One of the most popular fruits known for its magnesium content.
7. Avocados: Besides being a source of healthy fats, avocados also provide magnesium.
8. Dark Chocolate: High in magnesium, antioxidants, and other nutrients, making it a nutritious treat.²

What are the signs of magnesium deficiency in children?

Frank magnesium deficiency is relatively rare since it’s found in such a wide variety of foods, and because the kidneys do a good job of limiting excretion when intake is low. However, the average intake of magnesium is well below the recommended intake for disease prevention.¹ Magnesium deficiency impacts the gastrointestinal, neuromuscular, and cardiovascular systems.

Early symptoms include fatigue, weakness, poor appetite, and nausea, followed by muscle cramps or twitches, impaired speech, anemia, irregular heartbeat, tremor, and failure to thrive. Numbness, tingling, seizures, and personality changes may also occur. Later stages of magnesium deficiency induce rapid heart rate, cardiac fibrillation, and convulsions, often as a result of hypocalcemia or hypokalemia.¹

In children, the two most common symptoms of magnesium deficiency are constipation and poor sleep. Other symptoms include growing pains or cramps, headaches, frequent waking throughout the night, and abnormal energy. A magnesium deficiency may exacerbate existing conditions like migraines, ADD, ADHD, autism, and asthma. The body uses magnesium rapidly under stress, thus children may exhibit more significant symptoms of magnesium deficiency in times of stress. Children are also at an increased risk of insufficient magnesium due to their rapid growth and development.³ Children who are picky eaters and/or have sensory disorders are at the highest risk of insufficient intake.

Studies show that 48% of Americans in all age ranges consume less magnesium than the Estimated Average Requirements.² The Standard American Diet (SAD) excludes many fruits, vegetables, nuts, seeds, and whole grains, all of which are rich sources of magnesium. So although frank magnesium deficiency is rare, many Americans are at risk of magnesium inadequacy or a functional deficiency due to poor intake, poor absorption, or increased losses. People with gastrointestinal diseases such as Crohn’s disease, Celiac disease, and regional enteritis are at a greater risk of magnesium depletion due to the presence of chronic diarrhea and fat malabsorption.²

People with insulin resistance or type 2 diabetes have greater magnesium losses, secondary to high glucose concentrations in the kidneys which increases urinary excretion. Individuals struggling with alcoholism tend to have poor magnesium intake, malabsorption, renal dysfunction, and various other factors that contribute to magnesium deficiency.² Older adults are another population who tend to have lower dietary intake of magnesium, coupled with poor absorption and increased losses. Chronic conditions and multiple medications increase their risk of magnesium depletion. Other causes of magnesium insufficiency include poor nutrition (SAD), excess salt, coffee, and soda intake, chronic stress, chronic diarrhea, excessive menstruation, and intestinal parasites.¹

What lab test is best for diagnosing magnesium deficiency?

Diagnosing magnesium deficiency accurately involves several laboratory tests, as magnesium levels in the body can be difficult to measure precisely through a single test. The most commonly used tests include:

1. Serum Magnesium: This is the most common initial test for assessing magnesium status. However, it’s important to note that this test may not always accurately reflect total body magnesium levels, as less than 1% of the body’s magnesium is found in blood serum. According to the Mayo Clinic Laboratories here are the reference ranges for serum magnesium for pediatric patients:
   • 0-2 years: 1.6-2.7 mg/dL
   • 3-5 years: 1.6-2.6 mg/dL
   • 6-8 years: 1.6-2.5 mg/dL
   • 9-11 years: 1.6-2.4 mg/dL
   • 12-17 years: 1.6-2.3 mg/dL
   • >17 years: 1.7-2.3 mg/dL
2. RBC Magnesium: This test measures magnesium levels inside cells or in the bone, providing a more accurate assessment of magnesium status than serum levels. Intracellular magnesium tests can be more complex and are usually performed through specialized testing such as a red blood cell (RBC) magnesium test, which is considered more accurate for determining magnesium deficiency. Labcorp lists a RBC magnesium test reference range at 3.7-7.0 mg/dL for adults, but this lab test is considered experimental and is not cleared or approved by the Food & Drug Administration. I was not able to find an appropriate reference range for children.
3. 24-Hour Urinary Magnesium: This test measures the amount of magnesium excreted in the urine over a 24-hour period. It can be helpful in determining whether the body is losing too much magnesium. This test is often used in conjunction with other magnesium tests to provide a more comprehensive view of magnesium status. This test is best for patients where the provider suspects a metabolic disorder or congenital defect (e.g., Barter syndrome) or exposure to a certain drug (e.g., diuretics, aminoglycoside antibiotics) that causes magnesium wasting. Another alternative to this test may be a Magnesium/Creatinine ratio test.
4. Magnesium Loading (or Tolerance) Test: This test is considered the gold standard by some experts for diagnosing severe magnesium deficiency. It involves measuring urinary excretion of magnesium following the administration of a magnesium dose intravenously. It’s based on the principle that the body will retain magnesium if stores are low. However, due to its invasive nature, it’s not commonly used in routine clinical practice.

Among these, the RBC Magnesium Test is often considered more accurate for diagnosing magnesium deficiency than a serum magnesium test alone. This is because it reflects more accurately the magnesium status within cells, where the majority of the body’s magnesium is stored.

What medications can deplete magnesium?

Several medications can deplete magnesium. Loop diuretics (e.g., furosemide) and thiazide diuretics (e.g., hydrochlorothiazide) can increase urinary excretion of magnesium, leading to magnesium depletion, especially with long-term use. Proton pump inhibitors such as omeprazole and esomeprazole, used for treating acid reflux and gastroesophageal reflux disease (GERD), can decrease magnesium absorption when used for prolonged periods. Some antibiotics, especially the aminoglycoside class (e.g., gentamicin) and tetracyclines, can affect magnesium levels by either reducing absorption or increasing excretion. Long-term use of corticosteroids can lead to increased excretion of magnesium, among other electrolytes, potentially causing deficiencies. In diabetic patients high doses of insulin can lower serum magnesium levels by increasing urinary excretion. Certain chemotherapeutic agents can also cause magnesium depletion.

It should be noted that soil depletion of magnesium is another factor contributing to widespread magnesium insufficiency.

Signs of toxicity:

Toxicity is typically linked to over supplementation or found in individuals with renal failure. Symptoms of high magnesium include diarrhea, mental alterations, muscle weakness, nausea, irregular heartbeat, very low blood pressure and difficulty breathing. The tolerable upper limit for magnesium is 350 mg/day for adults and adolescents.¹ Diarrhea is the most common sign of excess magnesium intake and is a clue to reduce the dose or divide the total daily amount throughout the day.

Is magnesium supplementation safe for children?

Magnesium is generally a very safe supplement in patients with healthy kidneys. Diarrhea is a good self limiting indicator that the dose should be reduced or divided, but rarely do adverse effects tip into the unsafe category. However, patients with kidney disease should only use magnesium under the supervision of a physician or qualified nutritionist. The kidneys are the primary regulator of magnesium, and when they are impaired, magnesium may accumulate to unsafe levels in the blood. The safest way for most people to consume magnesium is by increasing their consumption of whole food sources such as vegetables, nuts, seeds, legumes, and whole grains, whenever possible.

What is the best type of magnesium?

There are many forms of magnesium available for supplementation, and they vary in their uses and bioavailability. The types of magnesium that are most efficiently absorbed in the gut are those that dissolve well in water.² Magnesium citrate, aspartate, lactate, and chloride are generally easier to absorb and more bioavailable than magnesium sulfate and magnesium oxide.²

The most common types of supplemental magnesium are magnesium oxide, citrate, glycinate, and L-threonate. Magnesium oxide is likely the type you’ll find on a grocery store shelf, but it’s poorly absorbed and isn’t effective at raising magnesium levels in the body. It’s often used for heartburn and constipation. Magnesium citrate is much more bioavailable and is useful for short-term constipation relief. Use caution with magnesium citrate if constipation is not the primary concern since it can cause loose stools. Magnesium glycinate is also highly bioavailable and is less likely to create loose stools. For this reason, it’s an option for improving sleep, headaches, anxiety, depression, insomnia, and relieving menstrual cramps. It may be helpful in reducing exercise induced muscle soreness. Magnesium threonate is unique in that it crosses the blood-brain barrier and can be supportive for brain health such as depression and memory loss (Zarate).

Other, less common forms of magnesium include magnesium malate, chloride, lactate, and sulfate. In animal studies, magnesium malate is the most readily absorbed type of magnesium. It is used for headaches, constipation, heartburn, and to increase magnesium status in the body. Magnesium malate is also easier on the GI tract and although the evidence is weak, it’s often used in chronic fatigue syndrome and fibromyalgia (Ferreira). Magnesium chloride is easily absorbed and used for constipation and heartburn when consumed orally, or to relieve muscle soreness when used topically. Magnesium lactate is gentler on the digestive tract and some small studies suggest its use for managing stress and anxiety (Boyle). Magnesium sulfate is found in Epsom salts and may soothe sore muscles and relieve stress. The evidence to support such claims is rather limited, but many anecdotal accounts allude to its efficacy.

Magnesium supplements come in pills, gummies, powders, and liquids, and the delivery mechanism does not appear to influence absorption. As with all supplements, it’s important to choose one that’s been third party tested and has a USP or NSF certification. Make sure that the form you purchase is appropriate for your goals.

Here is a magnesium cheat sheet to reference:

• Magnesium citrate: readily absorbed and useful for short-term constipation relief.
• Magnesium glycinate: readily absorbed, less likely to create loose stools. May be useful for insomnia, headaches, anxiety, depression, relieving menstrual cramps, and soothing sore muscles.
• Magnesium malate: readily absorbed and used for headaches, constipation, heartburn, and to increase magnesium status in the body.
• Magnesium threonate: supports brain health, depression, and age related memory loss. Note this product tends to be significantly more expensive than the other forms of magnesium.
• Magnesium chloride: readily absorbed, best used topically to relieve muscle soreness.
• Magnesium lactate: gentler on GI, used for managing stress and anxiety.
• Magnesium malate: used in chronic fatigue syndrome and fibromyalgia.
• Magnesium sulfate: Epsom salts, doesn’t increase body stores of magnesium but may soothe sore muscles and relieve stress.
• Magnesium oxide: poorly absorbed, not effective at raising magnesium levels in the body.

Clinical use of magnesium in naturopathic pediatrics

Constipation

Magnesium citrate is an osmotic laxative used to treat occasional constipation. It works by pulling water into the intestines, making stool easier to pass. Since it promotes the pulling of water from other areas of the body, people using magnesium citrate must ensure adequate hydration. The research supporting magnesium citrate for treating chronic constipation is limited, however. Magnesium hydroxide, found in Milk of Magnesia, a product used to treat constipation, and magnesium oxide are other forms used for constipation. If chronic constipation is occurring, it’s important to consult with a physician and investigate the underlying cause. For more information about the use of laxatives in constipation please see our article: The rationale for long-term laxative therapy for kids with constipation

Restlessness and Insomnia

Low magnesium is associated with numerous sleep issues such as restless sleep, restless leg syndrome, difficulty falling and trouble staying asleep. Magnesium supports quality sleep by acting as a natural NMDA antagonist and GABA agonist, both of which have a relaxing effect on the brain and body.⁶ Magnesium supplementation has been associated with significant improvements in insomnia severity, the amount of time it takes to fall asleep, sleep quality, amount of time asleep, and a number of sleep promoting hormones. However studies have primarily been completed in adults and the elderly.⁷ One study in children

Another study showed a reduction in periodic limb movements during sleep in patients taking magnesium, suggesting more restful sleep.⁵ The best forms to consider for restlessness or insomnia are magnesium glycinate and magnesium threonate, though it can be more challenging to find this form of magnesium in a product that children can tolerate.

Anxiety and Depression

Magnesium insufficiency is associated with an increased stress response and a greater risk of anxiety and depression. Unfortunately, stress promotes rapid use of magnesium, locking people into a negative feedback loop. As mentioned above, magnesium helps promote a healthier balance of stress hormones which not only promotes restful sleep, but may play a role in reducing anxiety. Magnesium also promotes muscle relaxation, which may ease some of the physiological symptoms associated with anxiety.

Magnesium sulfate, glycinate, and taurinate have been successfully used in managing depression.⁵ Magnesium is required to convert tryptophan to serotonin, one of the primary neurotransmitters associated with mental health and mood. Additionally, magnesium is a natural NMDA receptor antagonist, contributing to the antidepressant effect. Studies show that low intake of magnesium is associated with depression in young adults.⁶ One study found that daily supplementation with magnesium leads to significant improvements in depression and anxiety symptoms regardless of age, gender, baseline severity of depression, or use of antidepressant medications. However, this study was not completed in children.⁷

Migraines and Headaches

Studies have found oral magnesium supplementation to be an effective tool for managing migraine headaches. In one study, oral magnesium reduced the frequency, duration, and intensity of migraines by 41% compared to 15.8% in patients who took a placebo.⁵ One study found a statistically significant association between low serum magnesium levels and the occurrence of migraines in children.¹⁰ Intravenous magnesium sulfate was shown to significantly improve all symptoms in patients experiencing aura, but had less of an effect on those with a common migraine.⁴ A recent study showed that supplementation for a 3-month treatment period with oral magnesium citrate improved frequency and severity of migraines.⁵ Magnesium might not work for everyone, but taken over several months may help reduce the severity and occurrence of migraine headaches.

Growing Pains

Although the research is rather limited, magnesium is often used as a remedy for growing pains in children. It’s likely that the role magnesium plays in muscle and bone development plays a part in easing symptoms associated with growing pains. Oral magnesium supplementation and topical magnesium lotions may be beneficial for achy muscles in rapidly growing children. It’s important to note that growing pains generally affect the muscles of the legs, particularly the chins, calves, and thighs. Both sides are usually affected in equal measure. If a child complains about joint pain, unilateral pain, or begins limping, this could be a sign of a more serious issue.

Cramps and Muscle Spasms

A common symptom associated with magnesium deficiency is muscle spasms or cramps, leading researchers to investigate if supplementation may be useful in preventing them, but the evidence is rather limited. One meta-analysis of seven randomized controlled trials found that magnesium supplementation had no greater benefit than a placebo in the general population, but may have a small impact on leg cramps in pregnant women.¹¹ Although supplementing with magnesium may not ward off all muscle spasms or cramps, ensuring adequate intake will reduce the risk of muscle spasms and cramps associated with magnesium deficiency.

Bone Health

Magnesium is well known for its role in promoting strong bones. Studies have found a direct correlation between magnesium consumption and bone mineral content and bone mineral density in children.¹² The amount of magnesium children consume is even more predictive of bone health than calcium consumption. Peak bone mass accrual happens during childhood and bone mineral density only continues to increase until aged 30, whereby it begins to decline. Adequate magnesium intake promotes healthy bone building in childhood that may protect them from osteoporosis in the future.

ADHD and Attention

It’s well known that dietary factors play a significant role in the etiology of ADHD. Studies have found consistently low serum and erythrocyte levels of magnesium in children with ADHD 9. One clinical study examined the effect of regular magnesium supplementation in children with ADHD who were deficient in magnesium.¹³ After six months of regular supplementation, the children taking magnesium (200 mg/d) showed significant improvements in hyperactivity, as measured by numerous psychometric scales.¹³

The mechanism of action may be consistent with the pharmaceutical treatments often given to children with ADHD. These drugs primarily act through dopamine receptors, while magnesium interacts with dopamine, serotonin, and inhibits NMDA release, with the net result being quite similar.¹⁴ There are numerous promising studies indicating magnesium supplementation as a tool for treating ADHD, but a large, double-blind clinical trial is necessary to draw broader conclusions.

Another interesting study examined the effect of a combination product including omega-3 and omega-6 fatty acids, magnesium, and zinc on behavioral and emotional issues in children with ADHD or hyperactivity.¹⁵After three months of supplementation, most subjects showed significant improvements in their attention, hyperactivity, and impulsivity, as well as fewer emotional problems and improvements in sleep. Although it’s difficult to tease apart what degree of the benefits were from the magnesium, it is clear that dietary intervention can significantly improve symptoms associated with ADHD and hyperactivity. Magnesium is a cost effective and low risk intervention that has numerous behavioral benefits.

Asthma

Intravenous magnesium is often used in the emergency room setting in adults who do not respond to initial treatment for acute asthma attacks.¹⁶ These effects have been found in children with moderate to severe asthma when used in conjunction with bronchodilators and steroids.¹⁶ Furthermore, magnesium insufficiency may play a role in severe bronchospasm associated with asthma.⁵

Other conditions in adults – cardiovascular disease prevention, metabolic syndrome, etc.

Magnesium has a hand in so many body processes and research continues to connect optimal magnesium intake with disease prevention. Studies suggest that adults with higher magnesium intake have a lower risk of developing metabolic syndrome, myocardial infarction, congestive heart failure, and hypertension.⁵ Although these aren’t conditions we tend to consider for children, disease prevention

begins in childhood. Ensuring optimal magnesium intake helps set children up for a future of health and longevity.

Summary:

Magnesium is a mineral with a hand in over 300 enzymatic processes throughout the body, so it’s no wonder why it has such wide reaching effects on the body and brain. Magnesium has a role in protein and DNA synthesis, bone development, muscle and nerve function, energy production, blood glucose and blood pressure regulation. There are numerous forms of magnesium supplementation available, and they vary in function and bioavailability. Supplementation with magnesium has been used for constipation, sleep, bone health, migraines, anxiety, depression, and ADHD. Oral and topical magnesium are anecdotally beneficial for growing pains, cramps, and muscle spasms, although the research is limited. Supplementing with magnesium is generally quite safe, but individuals with renal dysfunction must consult with their physician before beginning a supplement. The safest way to obtain magnesium is by eating plenty of whole foods like dark leafy greens, nuts, seeds, legumes, and whole grains. More and more research is connecting optimal magnesium intake with disease prevention, and encouraging children to eat a variety of magnesium rich foods is bound to set them up for a healthier future.

References:

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Information from this article was compiled with assistance from Kayla Martin, CNS (Certified Nutrition Specialist).