Magnesium: the Overlooked Nutrient That Supports Sleep, Focus, and Growth
Parents often hear about calcium for strong bones and iron for energy, but what about magnesium? This important mineral helps kids sleep well, stay focused, digest food, and build strong muscles and bones. Even though most Canadian children aren’t clinically deficient, many may not be getting enough magnesium each day to fully support their growth, mood, and development. (1). And because magnesium works quietly behind the scenes, its role in kids' overall wellness often goes unnoticed.
Let’s take a closer look at why this mineral matters, and how to make sure your child is getting enough.
What Does Magnesium Do?
Magnesium is involved in over 300 processes in the body and plays a vital role in helping kids stay calm, energized, and growing strong (1).Supports Brain and Nerve Function: Magnesium helps regulate nerve signals and calm the nervous system by balancing calcium’s excitatory effects (2, 3). Children with lower magnesium levels have shown more hyperactivity and inattention, especially in studies involving kids with ADHD (4).
· Builds Strong Bones: Over half of the body’s magnesium is stored in the bones, where it supports bone density and structure (1). Low intake during childhood has been linked to lower bone mineral density in later life (1).
· Promotes Better Sleep and Mood: Magnesium plays a role in regulating melatonin and GABA, both key in promoting sleep and reducing anxiety (2).
· Supports Energy and Digestion: Magnesium is essential for cellular energy production and normal muscle function, including smooth muscle activity in the digestive tract (2, 5).
How Much Do Kids Need?
In Canada, recommended intake levels are based on the Dietary Reference Intakes (DRIs) developed by the Institute of Medicine and endorsed by Health Canada (1).
Ages 1–3: 80 mg/day
Ages 4–8: 130 mg/day
Ages 9–13: 240 mg/day
These values represent the Recommended Dietary Allowance (RDA) — the average daily amount needed to meet the nutritional needs of nearly all healthy children in each age group (1).
Where Can Kids Get Magnesium?
Magnesium is naturally found in a wide variety of foods, especially those that are plant-based and high in fiber. According to Health Canada nutrient data, magnesium-rich foods include:
· Whole grains – Oats, brown rice, quinoa, whole wheat bread (6)
· Legumes – Lentils, black beans, chickpeas, soybeans (6, 7)
· Leafy greens – Spinach, kale, Swiss chard, edamame (6)
· Nuts and seeds – Almonds, cashews, sunflower seeds, pumpkin seeds, flax, chia (6, 7)
· Fruits – Bananas, avocados, dried figs (6)
· Dairy and alternatives – Plain yogurt, soy beverages, milk (moderate sources) (6, 7)
· Fish – Salmon and mackerel also contribute small amounts (6, 7)
For example, a ½ cup of cooked spinach provides around 78 mg, and 2 tablespoons of almond butter offers 80 mg, enough to meet nearly 100% of the daily need for toddlers (6).
What Affects Absorption?
Naturally occurring magnesium in food is safe and well-absorbed. Phytates,natural compounds found in whole grains and legumes, can slightly reduce magnesium absorption, but overall intake is more important than absorption percentage (5). Excess calcium or zinc supplements may interfere with magnesium absorption if taken in large amounts (6).
Tips to Help Kids Try Magnesium-Rich Foods
Introducing new foods can take time, especially when it comes to vegetables, legumes, or whole grains. These simple strategies can help make the process smoother:
Try pairing new foods with familiar favorites. For example, mixing lentils into spaghetti sauce or adding spinach to a smoothie makes magnesium-rich ingredients feel less intimidating.
Let kids help with meal prep. Involving them in washing, stirring, or choosing ingredients builds curiosity and comfort around new foods.
Serve small portions without pressure. Offering foods more than once, in a relaxed setting, helps children become more willing to taste and accept them over time (1).
References:
1. Institute of Medicine . Standing Committee on the Scientific Evaluation of Dietary Reference Intakes. Dietary reference intakes : for calcium, phosphorus, magnesium, vitamin D, and fluoride. Washington, D.C: National Academy Press; 1997.
2. Volpe SL. Magnesium in Disease Prevention and Overall Health. Advances in nutrition (Bethesda, Md). 2013;4(3):378S-383S.
3. Gröber U, Schmidt J, Kisters K. Magnesium in Prevention and Therapy. Nutrients. BASEL: Mdpi; 2015;7(9):8199–226.
4. Hemamy M, Parast VM, Askari G. Effect of Magnesium Supplementation on Children with Attention Deficit Hyperactivity Disorder (ADHD). Journal of nutrition and food security. 2017;2(4):318–23.
5. Uwitonze AM, Razzaque MS. Role of Magnesium in Vitamin D Activation and Function. Journal of Osteopathic Medicine (Online). 2018;118(3):181–9.
6. Health Canada. Canadian Nutrient File – Standard Reference [Internet]. Ottawa (ON): Government of Canada; 2023 [cited 2025 Jun 24]. Available from: https://food-nutrition.canada.ca/cnf-fce/
7.Schwalfenberg G, Genuis SJ, Kucuk O. The Importance of Magnesium in Clinical Healthcare. Scientifica (Cairo). 2017;2017(2017).