Leg pain can have many different causes, from injuries to medical conditions like arthritis or diabetes. One potential cause that is sometimes overlooked is a lack of the mineral magnesium. Magnesium plays several important roles in the body and low levels may lead to muscle cramps and discomfort. In this article, we will explore the link between magnesium deficiency and leg pain.
What is magnesium and what does it do in the body?
Magnesium is an essential mineral that is involved in over 300 biochemical reactions in the body. It helps maintain normal nerve and muscle function, supports a healthy immune system, keeps the heart rhythm steady, and helps bones remain strong.
Some key functions of magnesium include:
- Regulates muscle and nerve transmission
- Supports bone health
- Involved in energy production
- Helps regulate blood pressure
- Required for protein and DNA synthesis
Magnesium works together with calcium to support musculoskeletal health. About 60% of all magnesium in the body is found in the bones.
The recommended daily allowance (RDA) for magnesium is 400-420 mg per day for men and 310-320 mg per day for women. Foods high in magnesium include green leafy vegetables, nuts, seeds, beans, lentils, whole grains, and some fruit.
What causes magnesium deficiency?
Magnesium deficiency is common, with some estimates indicating that up to half of all Americans do not get enough magnesium in their diets. Causes of magnesium deficiency include:
- Inadequate dietary intake – not eating enough magnesium-rich foods
- Malabsorption issues – health conditions that impair the body’s ability to absorb magnesium from food
- Chronic alcoholism
- Older age – less efficient magnesium absorption
- Certain medications, like diuretics, proton pump inhibitors, and some diabetes medications
- Poorly controlled diabetes – increased urinary magnesium excretion
People with gastrointestinal disorders, diabetes, alcohol dependence, and older adults are at higher risk of magnesium deficiency.
Signs and symptoms of magnesium deficiency
Mild magnesium deficiency may have subtle symptoms or none at all. More severe deficiency can cause noticeable effects:
- Muscle cramps or spasms
- Abnormal heart rhythms
- Muscle weakness and fatigue
- Loss of appetite
- Nausea and vomiting
- Restless legs syndrome
- Bone loss
- Numbness or tingling
- Coronary spasms
- Personality changes
- Abnormal heart rhythms
As magnesium plays a key role in muscle function, a deficiency can manifest with muscle cramps, spasms, and soreness. Leg cramping at night is particularly common.
Magnesium deficiency can also cause hypocalcemia (low calcium levels), as magnesium is needed for proper calcium absorption and metabolism.
Can lack of magnesium cause leg pain?
Yes, magnesium deficiency is a known potential cause of chronic leg pain. Let’s examine the evidence surrounding the link between low magnesium and leg pain:
Muscle cramps and soreness
Muscle cramps are an obvious manifestation of magnesium deficiency. The mineral is required for proper muscle contraction and relaxation. Without enough magnesium, muscles are easily irritated and prone to painful cramping and spasms.
Leg muscles seem to be particularly susceptible to magnesium deficiency. Nighttime leg cramps are a classic sign of magnesium deficiency.
Research has found that magnesium supplementation can reduce leg cramp frequency and severity in people with frequent leg cramps.
Restless legs syndrome
Restless legs syndrome is a neurological disorder characterized by uncomfortable sensations in the legs along with an irresistible urge to move them. It often causes worse symptoms in the evening and at night.
Several studies have found that people with restless legs syndrome have lower magnesium levels. Magnesium supplementation has been shown to reduce restless legs symptoms in some individuals.
Peripheral neuropathy is nerve damage that can cause numbness, tingling, and pain in the hands and feet. Diabetic neuropathy is a common form caused by elevated blood sugar.
Researchers have found associations between low serum magnesium levels and peripheral neuropathy in diabetics. Magnesium supplementation may help improve neuropathic pain, presumably by protecting the nervous system.
Chronic pain conditions
Chronic pain disorders like fibromyalgia are characterized by widespread muscle tenderness and pain. Some research points to links between magnesium deficiency and fibromyalgia, possibly due to resulting muscle tension, inflammation, and nerve dysfunction.
Small studies have also found that magnesium supplementation may reduce pain and tender points in fibromyalgia patients. Larger trials are still needed.
How does lack of magnesium cause leg cramps and pain?
The exact mechanisms behind how magnesium deficiency contributes to leg pain and cramps are not fully understood. Here are some of the ways it may affect musculoskeletal health:
- Inadequate calcium absorption – magnesium is required for the parathyroid glands to properly regulate calcium levels. Low magnesium can cause hypocalcemia.
- Muscle excitability – magnesium helps regulate nerve impulses to muscles. Without enough present, muscles become hyperstimulated.
- Inflammation – magnesium modulates inflammatory cytokines. Deficiency may increase inflammatory responses.
- Reduced blood flow – magnesium helps blood vessels dilate. Deficiency may reduce microcirculation in muscles and nerves.
- Mitochondrial dysfunction – magnesium is needed for ATP energy production. Lack of it impairs cellular metabolism.
Reduced magnesium ultimately makes muscles more irritable and sensitive to cramping. It also likely impairs nerve function. Inflammation and oxidative stress may further damage muscles and nerves over time.
Other causes of leg pain
While magnesium deficiency is one potential cause of leg discomfort, many other things can also contribute to leg pain, including:
- Muscle strain or trauma
- Nerve compression (sciatica)
- Vascular diseases
- Autoimmune disorders
- Neurological diseases
Some of the most common causes of leg pain include arthritis, peripheral artery disease, sciatica, diabetic neuropathy, night cramps, venous insufficiency, and musculoskeletal injuries.
A full medical workup is usually needed to determine the underlying reason for leg discomfort. Magnesium testing can be part of this process.
When to suspect magnesium deficiency as a cause
Magnesium deficiency should be on your radar as a potential cause of leg pain if you have:
- Frequent muscle cramps in the legs, especially at night
- Restless legs syndrome symptoms
- Widespread chronic muscle pain and tenderness
- Tingling or numbness in the feet and legs
- Risk factors for magnesium deficiency, such as alcoholism, malabsorption disorders, older age
Nighttime leg cramps and restless legs syndrome are particularly suggestive, as research links these conditions to low magnesium levels.
People with chronic health conditions like diabetes, celiac disease, Crohn’s disease, and chronic alcoholism are also prone to magnesium deficiency and should have their levels checked.
How is magnesium deficiency diagnosed?
Magnesium deficiency can be difficult to diagnose conclusively, but some helpful tests include:
- Serum magnesium test – This measures the amount of magnesium in the blood. Levels below 0.75 mmol/L indicate deficiency.
- RBC magnesium test – Measures magnesium levels within red blood cells, giving a longer-term picture than the serum test.
- 24-hour urine test – Collects a full day’s worth of urine to measure total magnesium excretion. Elevated losses indicate deficiency.
- EXA test – Uses blood sample to directly measure ionized magnesium, the form that is biologically active.
These laboratory tests can help confirm or rule out magnesium deficiency. However, no single test is considered the gold standard. Magnesium testing is imperfect and many doctors also rely on signs and symptoms.
Can lack of magnesium cause leg pain at night?
Yes, magnesium deficiency is a well-established potential cause of leg pain at night. Nocturnal leg cramps (also called “charley horses”) are sudden painful spasms that often strike at night while lying in bed. They are highly associated with magnesium deficiency.
Up to 60% of adults occasionally suffer from nocturnal leg cramps. Studies have found that magnesium supplementation can reduce the frequency and severity of leg cramps at night. It restores normal muscle relaxation and eases painful cramping.
Older adults are particularly prone to nighttime leg cramps and magnesium deficiency because of reduced dietary intake, medication use, and age-related changes in magnesium metabolism. Ensuring daily magnesium intake meets the RDA may help prevent night cramps.
Can magnesium deficiency cause lower leg pain?
Yes, magnesium deficiency can manifest with pain, cramps, or discomfort in the lower leg muscles like the calves, shins, and feet.
Lower leg muscles seem especially prone to issues from magnesium deficiency. Potential reasons include:
- Lower legs are used heavily during daily activities like walking, putting strain on the muscles
- Reduced blood circulation in the lower extremities
- Nighttime leg cramps that affect the feet and calf muscles
- Gravity causes fluid accumulation in lower legs, which may exacerbate magnesium depletion
Typical lower leg symptoms from low magnesium include:
- Foot or toe cramps, like arch cramping
- Tight, sore, or tired calves
- Heel pain or spasms
- Diffuse achiness or tenderness in the lower leg
- Restless legs symptoms
If you have unexplained calf, foot, or heel pain, ask your doctor about checking magnesium levels.
Can lack of magnesium cause swelling in the feet and legs?
Some studies suggest that magnesium deficiency can contribute to swelling (edema) in the lower extremities like the feet and ankles.
This may occur because low magnesium levels allow excess calcium to enter muscle cells. This disrupts cellular function and can cause fluid retention and swelling.
There is also some evidence that magnesium supplementation may improve edema in congestive heart failure patients. Optimizing magnesium intake may have protective effects on foot and leg swelling.
Can magnesium deficiency cause nerve pain in legs?
Potentially yes. Magnesium is involved in normal nerve conduction, so deficiency may impair nerve function and lead to sensations of pain, numbness, or tingling.
Some specific examples of how low magnesium could contribute to nerve leg pain include:
- Hyperexcitability of nerve fibers in the legs
- Worsening diabetic peripheral neuropathy
- Impaired microcirculation to peripheral nerves
- Central sensitization – heightened sensitivity of nerves to pain signals
Magnesium deficiency is unlikely to be the sole cause of nerve pain. But it may worsen pain and neuropathy in those already susceptible due to diabetes, alcoholism, chemotherapy, or other nerve damage.
Treatment for leg pain from magnesium deficiency
If a magnesium deficiency is contributing to your leg discomfort, the primary treatment is to increase your daily magnesium intake. Some options for restoring magnesium levels include:
Eat more magnesium-rich foods like spinach, avocado, nuts, seeds, beans, whole grains, dark chocolate, and fatty fish. Juicing leafy greens is an easy way to increase magnesium from foods.
Avoid refined grains and heavily processed foods, as these are low in magnesium.
Take oral magnesium supplements in forms like magnesium citrate, magnesium glycinate, magnesium malate, and magnesium threonate. Avoid magnesium oxide, as it has poor bioavailability.
The RDA for magnesium is 400-420 mg daily for most adults. Those with deficiency may need more to restore levels.
Epsom salt baths
Soaking in a warm bath with Epsom salts (magnesium sulfate) allows magnesium to absorb through the skin. Spend 20 minutes soaking a few times per week.
Address causes of deficiency
Get screened for conditions that deplete magnesium like diabetes and celiac disease. Stop medications that cause excess magnesium loss if possible.
Treat alcoholism and ensure adequate vitamin D status for proper magnesium absorption.
Can magnesium supplements help leg pain?
Yes, research indicates that magnesium supplements can reduce various types of leg pain, especially muscle cramps and restless legs syndrome.
Studies show magnesium supplements may help reduce leg pain by:
- Decreasing nighttime leg cramps up to 84%
- Reducing restless legs syndrome by up to 85%
- Improving symptoms of plantar fasciitis
- Easing neuropathic pain from diabetes, chemotherapy
- Lowering pain scores in fibromyalgia patients
Typical supplemental doses used in studies range from 250-500 mg elemental magnesium daily. Chelated forms like glycinate and citrate have better bioavailability than magnesium oxide.
Magnesium therapy may be most effective for those who have documented deficiency. But many people likely have at least mild deficiency that could benefit from more magnesium intake.
Risks and side effects of magnesium supplementation
Magnesium is very safe and generally well-tolerated. Mild side effects can include:
- Nausea, stomach cramps
- Facial flushing and swelling
Too much magnesium from supplements can lead to serious side effects like low blood pressure, respiratory depression, irregular heartbeat, and cardiac arrest.
However, this generally only occurs at extremely high doses far above the RDA. Intakes under 350 mg per day are not known to cause adverse effects in most people.
Those with renal failure are at higher risk for magnesium toxicity due to impaired excretion. Chronic diarrhea can also be a sign of excess magnesium intake.
Can magnesium deficiency cause leg weakness?
Yes, magnesium deficiency can potentially contribute to leg weakness or heaviness, as well as generalized muscle weakness.
Magnesium helps regulate signals between motor neurons and muscles. It also provides vital energy for muscle cells. Without enough magnesium present, leg muscles may feel weak and exhausted.
Research has found associations between low magnesium levels and impaired muscle function in the elderly. Giving magnesium supplements to seniors improved grip strength and leg muscle performance.
Diabetics and athletes are also at higher risk for muscle weakness when magnesium deficient. Maximizing magnesium intake can help maintain strength and function in the legs.
Magnesium deficiency appears to be a contributing factor to many cases of chronic leg pain. It can lead to symptoms like muscle cramps, spasms, soreness, numbness, and tingling, especially in the lower legs.
Those at risk for magnesium deficiency who have unexplained leg discomfort should have their levels checked. Optimizing intake through magnesium-rich foods and supplements can restore cellular function and reduce pain.
However, leg pain has many potential causes. Be sure to see a doctor for an accurate diagnosis rather than assuming magnesium deficiency is the culprit. Appropriate treatment depends on the underlying reason for pain.
Increasing magnesium intake, preferably through food sources, is beneficial for nearly everyone. Deficiency is extremely common and plays a role in various aspects of health. Restoring levels can help prevent painful musculoskeletal problems among many other benefits.