Magnesium is one of the most abundant minerals in the human body. It plays a role in over 300 biochemical reactions, including protein synthesis, muscle and nerve function, energy production, and blood sugar regulation.

Because the body cannot make magnesium on its own, dietary intake is essential. A deficiency—also known as hypomagnesemia—can lead to a range of health issues. And since only 0.3% of total body magnesium is found in serum, symptoms can often reveal deficiency better than lab tests.

1. Irritability and Mood Swings

Low magnesium levels can disrupt neurotransmitter activity, particularly serotonin and dopamine—key chemicals that regulate mood. This disruption may heighten irritability, emotional sensitivity, and make coping with stress more difficult. Magnesium deficiency is also being studied for its potential link to depressive symptoms.

2. Nausea and Digestive Upset

Magnesium contributes to proper gut motility by relaxing smooth muscles. A deficiency can slow digestion, leading to nausea, bloating, vomiting, or even constipation. Persistent gastrointestinal symptoms should prompt medical evaluation.

3. Loss of Appetite

Early signs of low magnesium may include decreased appetite. This could be due to slower digestion or changes in hunger hormones like leptin. Nausea and bloating from a deficiency may further reduce the desire to eat.

4. Fatigue and Low Energy

Magnesium is vital for ATP (adenosine triphosphate) production—the body’s main energy currency. Without enough magnesium, ATP cannot activate properly, which may leave you feeling exhausted both mentally and physically.

5. Numbness or Tingling in Extremities

Magnesium plays a critical role in nerve function. Inadequate levels can impair nerve transmission, leading to sensations like numbness, tingling, or even peripheral neuropathy. This condition can affect the hands, feet, or limbs.

6. Frequent Headaches or Migraines

Headaches can result from many factors, and magnesium deficiency is one of them. Low magnesium may cause constricted blood vessels or disrupted neurotransmitter function, contributing to tension headaches or more severe migraines.

7. Poor Sleep Quality

Magnesium helps regulate melatonin and calming neurotransmitters that aid in sleep. Deficiency can disrupt circadian rhythms and increase stress, both of which contribute to poor sleep quality or insomnia.

8. Muscle Cramps or Spasms

One of the most well-known signs of magnesium deficiency is muscle cramping. Magnesium is essential for relaxing muscles by balancing calcium and potassium levels. Without enough of it, muscles may contract involuntarily, often at night.

9. Irregular Heartbeat or Palpitations

Magnesium is essential for electrical conduction in the heart. A deficiency may result in palpitations, arrhythmias, or fluttering sensations in the chest. In severe cases, low magnesium can lead to dangerous heart rhythm problems.

Who’s at Risk for Magnesium Deficiency?

Certain populations have a higher risk of magnesium deficiency:

  • Older adults: Decreased absorption and increased loss through urine.

  • People with GI disorders: Conditions like Crohn’s or celiac disease impair absorption.

  • Individuals with type 2 diabetes: High glucose levels can increase magnesium excretion.

  • Those with alcohol dependence: Chronic alcohol use can impair magnesium uptake.

  • People on certain medications: Diuretics, PPIs, and immunosuppressants may lower magnesium levels.

How To Increase Magnesium Intake

You can support your magnesium levels through both diet and supplementation:

  • Eat more magnesium-rich foods like leafy greens, whole grains, legumes, seeds (especially chia and pumpkin), nuts, and fatty fish like salmon.

  • Magnesium supplements are available in various forms such as magnesium citrate and magnesium oxide. Some are more bioavailable than others, so talk to your healthcare provider before starting one.

A Quick Review

Magnesium is essential for many physiological processes. Deficiency symptoms range from fatigue and headaches to muscle cramps and palpitations. Because the body cannot produce magnesium, it’s important to consume enough through diet or supplements.

If you suspect a deficiency, speak with your doctor or dietitian to evaluate symptoms and determine the best course of action.