The Role of Magnesium in the Body

The Role of Magnesium in the Body

Magnesium is one of the most essential minerals in the body. It acts as a cofactor in more than 300 enzyme systems, influencing everything from bone strength to blood sugar regulation.

Here are the key systems where magnesium plays an important role:

1. Bone Health – About 60% of your body’s magnesium is stored in the bones. Bones are constantly breaking down and rebuilding; when breakdown exceeds rebuilding, it can lead to osteopenia or bone loss. Magnesium helps regulate this balance and supports the hormones involved in bone formation.
2. Nerve Function – Magnesium helps regulate nerve transmission and reduces overstimulation in the nervous system.
3. Glucose Control & Insulin Metabolism – Magnesium assists in insulin secretion and helps improve insulin sensitivity, which may support healthy blood sugar levels.

 

Understanding Magnesium Deficiency

Unfortunately, measuring magnesium levels isn’t simple. Serum magnesium tests are not always accurate because most magnesium is stored in tissues, not in the blood.

Here are a few ways magnesium levels can be assessed:

• Blood (plasma) tests – Commonly available, but least accurate.
• Urine collection tests – Low magnesium in urine can indicate deficiency.
• Magnesium load tests – Typically used only for patients with suspected kidney issues.

 

Dr. Peter Attia explains:

“We don’t have great ways to measure magnesium, and we often overlook it clinically unless kidney function is severely impaired.”

Magnesium and Migraines

Magnesium plays a crucial role in inhibiting the excitatory NMDA receptor pathway in the brain. Low magnesium levels can increase nerve excitation and contribute to migraines.

Studies show that 2–4g of IV magnesium can provide short-term relief from migraines (though this dose cannot be achieved orally).

The Interplay Between Vitamin D and Magnesium

Vitamin D and magnesium work together to support both bone and cardiovascular health. Vitamin D helps the body absorb magnesium. Magnesium is needed to activate and stabilize vitamin D into its usable form (25-hydroxy-vitamin D).

People with higher magnesium levels often experience more benefits from vitamin D when it comes to cardiovascular and cancer protection.

Magnesium for Hypertension and Heart Health

Chronic high blood pressure can damage blood vessels, increasing the risk of dementia and cognitive decline.

Research shows that magnesium supplementation (around 368mg/day) may:

• Relax and widen blood vessels
• Improve circulation and cardiovascular health
• Protect against vascular damage

 

Finding Your Optimal Magnesium Intake

Your magnesium needs depend on your physical activity, diet, and daily stress per pound of body weight.

For example:

A 100 lb individual would need about 5,000mg of magnesium glycinate per day, spread throughout the day.

Common forms include:

• Magnesium Glycinate (≈10% elemental magnesium)
• Magnesium Chloride (≈25% elemental magnesium)

It’s best to use multiple forms and routes of administration (oral, topical, etc.) for optimal absorption. With healthy kidneys, excess magnesium is naturally excreted. The most common side effect of taking too much orally is loose stools — your “bowel flush” level.

Once identified, stay just below that level for optimal intake.

Dr. Kapur’s Personal Example

“I weigh around 150 lbs and consume 10–15g of magnesium daily in various forms:

• 400mg magnesium glycinate with 200mg L-theanine upon waking
• 400mg magnesium glycinate after breakfast
• 1,000mg magnesium glycinate and 1,000mg L-theanine before bed
• ½ tsp (≈2.5g) magnesium chloride per liter of water (4–6 liters/day)
• Topical magnesium chloride spray in the morning and before/after workouts”

My magnesium intake has shifted over time—during a period of deficiency, I supplemented with 15 grams daily for six months. Currently, I maintain optimal levels with 3–5 grams per day.

Tips for Starting Magnesium Supplementation

• Start low and go slow: Begin with 400mg of magnesium glycinate or ¼–½ tsp magnesium chloride in water.
• If you don’t experience a bowel flush, increase gradually.
• If you do experience a flush early, you may be low in thiamine (B1), sodium, or potassium.

• • In that case, use topical magnesium and ensure adequate electrolytes.

• • Testing options:
    • RBC potassium/sodium
    • Thiamine and transketolase levels
    • Hair tissue mineral analysis (available at Directlabs.com)

To fully support your body, use 2–6 forms of magnesium, such as:

• Glycinate
• Chloride
• Taurate
• Malate
• Threonate

 

Spread doses throughout the day, but reserve your largest dose before bed, when the body performs most of its repair and detoxification processes.

Daytime doses should be smaller and taken with meals for best absorption.

Replenishing magnesium can take time, but the benefits for energy, mood, sleep, muscle recovery, and overall vitality are well worth it.

If you experience temporary skin irritation from topical magnesium, it may be due to detoxification and will improve as your body rebalances.

As always, if you have questions about magnesium or would like to discuss your specific needs, please schedule an appointment with me.

Thank you,

Dr. Kapur

KC Primary Care