How to Spot Magnesium Deficiency in Kids (And What to Do About It)

Magnesium may not be the flashiest nutrient, but it's one of the most important for growing bodies. From digestion to mood regulation, this mineral plays a role in over 300 functions in the body and yet, many kids aren’t getting enough.

If your little one is dealing with constipation, restlessness, or trouble sleeping, a magnesium deficiency could be part of the picture. Here’s how to spot the signs, what causes low magnesium in kids, and how to help restore healthy levels through food and gentle supplementation.

Why Magnesium Is Crucial for Kids

Magnesium supports:

• Regular bowel movements

• Muscle relaxation and nerve function

• Bone growth and calcium absorption

• Emotional regulation and sleep quality

• Immune health

Despite these benefits, dietary surveys show thatmany kids don’t meet their daily magnesium needs, especially those with limited diets or picky eating habits.¹

Common Signs of Magnesium Deficiency in Kids

Magnesium deficiency can be hard to diagnose based on lab tests alone, so it’s important to pay attention to symptoms. Here are the most common signs:

1. Constipation or hard poops

Magnesium helps draw water into the intestines and keeps the muscles of the gut moving. Low intake can lead to infrequent or difficult bowel movements.²

2. Muscle cramps or “growing pains”

Kids with low magnesium may experience nighttime leg cramps, muscle twitching, or general body discomfort.

3. Trouble falling or staying asleep

Magnesium plays a role in regulating the nervous system. A deficiency may lead to restlessness, trouble relaxing at bedtime, or difficulty staying asleep.³

Other signs can include low energy, irritability, and difficulty concentrating—but these are also common in kids for other reasons, so magnesium should be considered as part of a broader nutrition picture.

What Causes Magnesium Deficiency in Kids?

Several factors can contribute:

• Low intake of magnesium-rich foods (like greens, legumes, nuts, whole grains)

• Picky eating or limited variety in the diet

• Digestive issues that reduce absorption

• Excessive sweating or physical activity

• High intake of ultra-processed foods that displace nutrient-dense options

How Much Magnesium Do Kids Need?

According to the National Institutes of Health [4]:

These numbers reflect total intake from both food and supplements.

How to Restore Magnesium Levels

1. Add magnesium-rich foods

Incorporate more:

• Pumpkin seeds

• Black beans

• Spinach

• Avocados

• Bananas

• Oats

• Whole grain bread

Even small changes, like blending spinach into smoothies or sprinkling seeds on yogurt, can help.

2. Try a magnesium supplement designed for kids

For kids with persistent constipation or dietary gaps, a supplement may be helpful. Look for:

• Forms likemagnesium citrate (effective for gut motility) orglycinate (gentle on the tummy)

• Kid-safe doses (under 65 mg for toddlers, under 110 mg for kids 4–8)

• No artificial sweeteners, dyes, or fillers

Begin Health Expert Tip:

Try Growing Up Magnesium by Begin Health. It’s a magnesium supplement drink mix designed for kids 1+, with a gentle blend of citrate and glycinate, plus potassium and prebiotics for added gut support.

 

Summary

Magnesium deficiency in kids is more common than many parents realize and it often shows up as constipation, sleep issues, or muscle discomfort. With a mix of magnesium-rich foods and a gentle supplement when needed, you can help your kiddo get back on track and support a healthy gut, mind, and body.