Last updated: October 2026
Most children get enough magnesium from a varied diet, so supplements usually aren’t needed. In the UK, children need 85mg a day at ages 1 to 3, 120mg at 4 to 6, 200mg at 7 to 10, 280mg at 11 to 14 and 300mg at 15 to 18. Ask your GP before giving a child any supplement.
This guide covers how much magnesium children need, the best foods, the signs of low magnesium, what research says about sleep and ADHD, and how to choose a supplement safely if your GP suggests one.
How much magnesium do children need?
These are the UK reference nutrient intakes (RNIs), the amount that meets the needs of almost all children in each age group, from all sources:
| Age | Magnesium per day |
|---|---|
| 0 to 3 months | 55mg |
| 4 to 6 months | 60mg |
| 7 to 9 months | 75mg |
| 10 to 12 months | 80mg |
| 1 to 3 years | 85mg |
| 4 to 6 years | 120mg |
| 7 to 10 years | 200mg |
| 11 to 14 years | 280mg |
| 15 to 18 years | 300mg |
Babies get what they need from breast milk or formula. There’s no official UK upper limit for supplements in children, which is one more reason to check with a GP or pharmacist before giving one. For adults, see magnesium for women and stress in men.
Best magnesium foods for kids
| Food group | Child-friendly ideas |
|---|---|
| Wholegrains | Porridge oats, wholemeal toast, wholewheat pasta, brown rice, wholegrain cereals |
| Nuts and seeds | Peanut or almond butter, ground seeds stirred into yoghurt (whole nuts aren’t suitable for under-5s, as they’re a choking risk) |
| Beans and pulses | Baked beans, hummus, lentil soup, chickpeas in curries |
| Vegetables | Spinach in pasta sauce, peas, broccoli, potatoes with skins |
| Fruit | Bananas, dried apricots, avocado |
| Dairy and fish | Milk, yoghurt, salmon, mackerel |
| Treats | A little dark chocolate or cocoa in porridge |
A day of porridge, a wholemeal sandwich with peanut butter, a banana, beans on toast and a glass of milk covers a younger child’s needs comfortably.
Why children need magnesium
Magnesium is an essential mineral involved in hundreds of processes in the body. It’s needed for normal bone growth, muscle and nerve function, turning food into energy, and normal psychological function. Children need more as they grow, especially in their teens.
Signs of low magnesium in children
True magnesium deficiency is uncommon in healthy children. When it happens, it’s usually linked to a medical condition such as long-term diarrhoea, coeliac or Crohn’s disease, kidney problems, type 1 diabetes or certain medicines. Possible signs include tiredness, weakness, muscle cramps or twitches, poor appetite and feeling sick.
These signs are very general and have many other causes, so don’t guess. If you’re worried, see your GP, who can look at your child’s diet and arrange tests if needed. Children on very restricted diets, such as some autistic children or very fussy eaters, may benefit from a review with a dietitian.
Magnesium, sleep and ADHD: what the research says
| Topic | What studies show |
|---|---|
| ADHD | A 2019 review found children with ADHD tended to have lower blood magnesium than other children, but the studies varied widely |
| ADHD supplements | A 2021 trial in 66 children gave magnesium together with high-dose vitamin D under medical supervision and found fewer emotional problems after 8 weeks, but magnesium’s own effect can’t be separated out |
| Sleep | There are no good trials of magnesium for sleep in healthy children |
Magnesium isn’t a treatment for ADHD, autism or sleep problems. If your child has these difficulties, speak to your GP, who can refer you for assessment and support. For sleep, a regular bedtime routine and screen-free hour before bed help most children.
Should children take magnesium supplements?
Usually not. The NHS recommends vitamin supplements containing vitamins A, C and D for children aged 6 months to 5 years, and vitamin D in autumn and winter for older children, but magnesium isn’t routinely recommended. A GP might suggest it if a child has a diagnosed deficiency, a restricted diet or a medical condition affecting absorption.
Choosing a children’s magnesium supplement
- Only use products made for your child’s age, and follow the label dose exactly. Don’t give adult supplements, which can contain far more magnesium and added herbs.
- Choose a gentle form such as citrate or glycinate; too much of any form can cause diarrhoea and stomach ache.
- Watch the sugar in gummies and keep them out of reach, as they look like sweets. See are magnesium gummies safe for kids?
- Check medicines: magnesium can affect some antibiotics, so ask your pharmacist about timing.
- Avoid them if your child has kidney problems, unless a doctor advises otherwise.
Evopure’s magnesium products are made for adults and aren’t suitable for children. Learn more about the different forms in types of magnesium.
Magnesium spray and baths for children
Magnesium sprays and lotions are often marketed for children’s sleep and “growing pains”. There’s no good evidence that useful amounts of magnesium are absorbed through the skin, so any benefit is likely to come from the calming bedtime massage or warm bath itself. Sprays often sting, especially on dry or broken skin, and children’s skin is more sensitive. Ask a pharmacist before using one on a child. See does magnesium spray work?
Better ways to help children sleep
- A consistent bedtime and wake time, including at weekends where possible.
- A calm 30 to 60 minute routine: bath, pyjamas, teeth, story, lights out.
- Screens off at least an hour before bed, and out of the bedroom.
- A cool, dark, quiet room.
- Daylight and active play during the day.
- No caffeine: watch out for cola, energy drinks and chocolate in the evening.
- Time to talk about worries earlier in the evening, not at lights out.
Melatonin is prescription-only in the UK, including for children. See melatonin in the UK.
FAQs
How much magnesium does a child need a day?
In the UK: 85mg at 1 to 3 years, 120mg at 4 to 6, 200mg at 7 to 10, 280mg at 11 to 14 and 300mg at 15 to 18, from all sources.
Can children take magnesium?
Most children get enough from food. Only give a supplement made for their age, and check with your GP or pharmacist first.
Does magnesium help children sleep?
There’s no good evidence in healthy children. A regular bedtime routine helps most children; see your GP if sleep problems continue.
Is magnesium good for children with ADHD?
Children with ADHD may have lower magnesium levels, but supplements aren’t a proven treatment. Talk to your GP or your child’s specialist.
Can children take magnesium glycinate?
Glycinate is a gentle form, but only use a product designed for children, at the dose on the label, and check with a GP or pharmacist first.
What foods are high in magnesium for kids?
Wholegrains, peanut butter, beans and lentils, leafy greens, bananas, milk, yoghurt and oily fish.
Can a child have too much magnesium?
From food, no. Too much from supplements can cause diarrhoea, nausea and stomach cramps, and is more serious for children with kidney problems.
Is magnesium spray safe for kids?
Little is absorbed through the skin and sprays can sting. Ask a pharmacist before using one on a child.
Sources
- British Nutrition Foundation (2021). Nutrition requirements: reference nutrient intakes for minerals.
- NHS. Vitamins for children.
- NHS. Vitamins and minerals: magnesium.
- Effatpanah M et al (2019). Magnesium status and attention deficit hyperactivity disorder (ADHD): a meta-analysis. Psychiatry Research.
- Hemamy M et al (2021). The effect of vitamin D and magnesium supplementation on the mental health status of attention-deficit hyperactive children: a randomized controlled trial. BMC Pediatrics.
This guide is general information, not medical advice. Evopure supplements are for adults only.
