Magnesium for Kids and Teens: What Parents Should Know Before Giving a Supplement
By Toni Kim, MD — Founder & Board-Certified Pediatric Endocrinologist
Magnesium gummies, powders and drink mixes are increasingly marketed directly to parents.
They promise help with sleep, constipation, stress, headaches, cramps and focus.
Some children may benefit from magnesium.
But in pediatrics, the reason, form and dose matter.
The short answer
Children can take magnesium when there is an appropriate reason, but adult supplement doses should not automatically be used in children.
Before giving a supplement, ask:
- Why are we giving magnesium?
- How much does the child already get from food?
- What is the child's age?
- How much elemental magnesium is actually in the product?
- What medications does the child take?
- Is kidney function normal?
- Has the symptom itself been evaluated?
For an explanation of the different formulations, start with Types of Magnesium.
How much magnesium do kids need?
Recommended total magnesium intake varies by age.
| Age |
Recommended intake |
| Birth–6 months |
30 mg/day |
| 7–12 months |
75 mg/day |
| 1–3 years |
80 mg/day |
| 4–8 years |
130 mg/day |
| 9–13 years |
240 mg/day |
| Boys 14–18 |
410 mg/day |
| Girls 14–18 |
360 mg/day |
These values represent total daily intake, primarily from food and beverages.
The number parents often misunderstand: the supplemental upper limit
The upper limit for magnesium from supplements and medications is a different number.
| Age |
Supplemental upper limit |
| 1–3 years |
65 mg/day |
| 4–8 years |
110 mg/day |
| 9–18 years |
350 mg/day |
No supplemental upper limit has been established for infants under 1 year.
These limits do not include magnesium naturally present in food.
The RDA tells us roughly how much magnesium the body needs.
The supplemental upper limit tells us how much magnesium from supplements and medications can generally be consumed without increasing the risk of adverse effects in healthy people.
They answer different questions.
Which type of magnesium is best for kids?
There is no universal pediatric winner.
Magnesium glycinate
Glycinate is commonly considered when a family wants supplemental magnesium without a strong laxative effect.
Learn more about magnesium glycinate.
Magnesium citrate
Citrate may make sense when constipation is also part of the clinical picture because it can loosen stool.
Learn more about magnesium citrate.
Deciding between those two?
Compare magnesium glycinate vs citrate.
Magnesium oxide
Oxide has lower fractional absorption and may produce more pronounced GI effects.
It has also been studied in pediatric migraine and bone-health research.
Learn more about magnesium oxide.
Magnesium L-threonate
L-threonate has emerging adult cognition research.
That research does not establish routine pediatric benefit for memory, attention or sleep.
Learn more about magnesium L-threonate.
Can magnesium help kids sleep?
Maybe in selected circumstances.
But the strongest sleep evidence currently comes from adult studies, not robust pediatric trials.
Before treating a child's sleep problem with magnesium, look at:
- bedtime and wake time
- screens
- caffeine
- anxiety
- snoring
- restless sleep
- restless legs symptoms
- medications
- puberty
- circadian delay
Poor sleep is a symptom. It is not a magnesium diagnosis.
Read the adult evidence in Best Magnesium for Sleep.
What about magnesium for constipation?
Forms such as citrate, oxide and hydroxide can produce osmotic laxative effects.
But persistent constipation in a child deserves evaluation rather than endless supplement experimentation.
What about magnesium and pediatric migraine?
Magnesium has been studied for pediatric migraine prevention.
One study used magnesium oxide at approximately 9 mg/kg/day divided three times daily.
Results were equivocal.
That is a research dose, not a recommendation for parents to calculate and use at home.
What about magnesium and bone health?
Magnesium contributes to normal bone physiology.
A randomized trial in girls ages 8–14 with relatively low magnesium intake evaluated 300 mg/day of elemental magnesium as magnesium oxide for 12 months.
It produced a modest increase in hip bone mineral content.
Again:
A clinical trial dose is not automatically a routine supplement recommendation.
Can too much magnesium be dangerous?
Yes.
The most common effects of excessive supplemental magnesium are:
- diarrhea
- nausea
- abdominal cramping
Very high magnesium levels can be much more serious.
Risk is greater when kidney function is impaired because the kidneys normally help remove excess magnesium.
What medications interact with magnesium?
Magnesium can interfere with absorption of certain medications, including some:
- antibiotics
- bisphosphonates
Timing and clinical circumstances matter.
This is one reason “it's just a mineral” is not enough of a safety assessment.
Foods high in magnesium
Whenever practical, food is the first place to look.
Sources include:
- pumpkin seeds
- almonds
- cashews
- peanuts and peanut butter
- beans
- edamame
- spinach and other leafy greens
- whole grains
- fortified cereals
- milk
- yogurt
Frequently Asked Questions
Can kids take magnesium?
Yes, when there is an appropriate reason and the elemental magnesium dose is appropriate for the child's age and clinical situation.
How much magnesium does a child need?
Recommended intake ranges from 30 mg/day in young infants to 360–410 mg/day in older teenagers, depending on age and sex.
Is the magnesium upper limit the same as the RDA?
No. The recommended intake reflects total magnesium needs. The upper limit applies specifically to magnesium from supplements and medications, not food.
Is magnesium safe for kids' sleep?
It may be appropriate in selected situations, but pediatric sleep problems should not automatically be attributed to magnesium deficiency.
What magnesium is best for constipation in kids?
Several forms can have laxative effects, including citrate and oxide, but recurring pediatric constipation deserves appropriate evaluation.
Can a child take an adult magnesium gummy?
Not automatically. Check the elemental magnesium amount, child's age, other ingredients, medications and why the supplement is being considered.
What happens if a child gets too much magnesium?
The most common symptoms are diarrhea, nausea and abdominal cramping. More serious toxicity can occur with very high exposure, particularly when kidney function is impaired.
Want Help Deciding Whether Magnesium Belongs in Your Child's Plan?
Parents are often left choosing between gummies, powders, citrate, glycinate and sleep products without knowing what their child actually needs.
At LIFE Pediatric Endocrinology, Dr. Toni Kim looks at growth, puberty, nutrition, sleep, metabolic health, medications, symptoms and laboratory findings when appropriate before deciding whether a supplement belongs in the plan.
Sometimes magnesium does.
Sometimes it does not.
Talk With LIFE About Your Child's Nutrition and Supplement Plan →
About Toni Kim, MD
Toni Kim, MD, is a board-certified pediatric endocrinologist and Founder of LIFE Pediatric Endocrinology.
Her clinical work includes growth, puberty, thyroid disease, diabetes, metabolic health, nutrition and individualized pediatric endocrine care.
Learn more about Dr. Toni Kim.
References
Medical Disclaimer
This article is for educational and informational purposes only and is not a substitute for individualized medical advice, diagnosis or treatment. Magnesium needs, supplement dosing, medication interactions and safety vary with age, diet, medical history, kidney function, medications and the reason supplementation is being considered. Do not start, stop or change a child's supplement or medication regimen based solely on this article. Speak with your child's pediatrician or qualified healthcare professional for personalized guidance. Seek immediate medical care for a medical emergency.
