Fatigue, muscle cramps and nausea are common complaints, but they can also be early signs of magnesium deficiency. Magnesium is involved in more than 300 enzyme systems in the body, and when digestive conditions interfere with how it’s absorbed, deficiency symptoms can build gradually and go unrecognized for months.
Below are signs of magnesium deficiency to watch out for, why digestive health plays a bigger role than most people realize and when it’s time to talk to a gastroenterologist or registered dietitian.
What Is Magnesium Deficiency?
Magnesium deficiency, also called hypomagnesemia, happens when the body doesn’t have enough magnesium to support normal muscle, nerve, heart and digestive function. According to the National Institutes of Health (NIH) Office of Dietary Supplements, symptomatic magnesium deficiency from diet alone is uncommon in otherwise healthy people because the kidneys are efficient at conserving magnesium. Deficiency becomes far more likely when certain health conditions, medications or chronic digestive issues cause the body to lose magnesium faster than it can be replaced.
Globally, researchers estimate that roughly 31% of people—or about 2.4 billion individuals—fall short of recommended magnesium intake levels, making inadequate magnesium one of the more common nutrient gaps worldwide.
Why Digestive Health Is Closely Linked to Magnesium Levels
The digestive system is where magnesium from food and supplements is absorbed into the body, primarily in the small intestine. When digestive issues disrupt that process, magnesium absorption can drop even if a person’s diet looks reasonably balanced. The NIH Office of Dietary Supplements specifically identifies people with gastrointestinal diseases as a group at higher risk of magnesium inadequacy.
Common digestive causes include:
- Chronic diarrhea or malabsorption disorders, such as Crohn’s disease, celiac disease or ulcerative colitis, which reduce the intestine’s ability to absorb magnesium
- Long-term use of proton pump inhibitors (PPIs), a class of acid-reducing medications the FDA has linked to low magnesium levels with extended use
- Gastric or bowel surgery, which can shorten the digestive tract’s absorptive surface
- Persistent nausea or vomiting, which limits intake and increases mineral losses
This is why someone dealing with ongoing digestive issues may also be dealing with magnesium deficiency without realizing the two are connected.
5 Signs of Magnesium Deficiency
| Sign | What It Looks Like | Why It Happens |
| Loss of appetite and nausea | Reduced desire to eat, an upset stomach or vomiting | Among the earliest and most common signs of magnesium deficiency, per the NIH |
| Fatigue and weakness | Persistent tiredness not explained by sleep or activity level | Magnesium is required for cellular energy production |
| Muscle cramps and twitching | Involuntary muscle contractions, spasms or cramping, often in the legs | Magnesium helps regulate muscle contraction and relaxation |
| Numbness or tingling | A “pins and needles” sensation, often in the hands or feet | Magnesium supports normal nerve signaling |
| Abnormal heart rhythm | Irregular or rapid heartbeat (palpitations) | Severe deficiency can disrupt the heart’s electrical activity and calcium and potassium balance |
If digestive symptoms like chronic diarrhea, abdominal pain or unexplained weight change are also present alongside these signs, it’s worth discussing with your provider at the same visit, since one may be driving the other.
Other Risk Factors Beyond Digestive Issues
Digestive conditions are one of the most common and overlooked contributors to magnesium deficiency, but they aren’t the only risk factor. The NIH Office of Dietary Supplements also identifies the following groups as being at higher risk:
- Older adults: since magnesium absorption tends to decrease with age while urinary magnesium excretion increases
- People with type 2 diabetes: particularly those with poorly controlled blood sugar
- People with chronic alcohol use: which affects both magnesium intake and absorption
Anyone in one of these groups who is also experiencing digestive symptoms may be facing a compounded risk, which is another reason to bring both issues to your provider’s attention rather than addressing them separately.
How Magnesium Deficiency Is Diagnosed
Magnesium deficiency is typically identified through a blood test that measures serum magnesium levels, often alongside calcium and potassium, since severe deficiency can throw off both. However, because most of the body’s magnesium is stored in bone and soft tissue rather than blood, a normal serum result doesn’t always rule out a deeper deficiency, which is one reason healthcare providers weigh lab results together with symptoms, digestive history and medication use.
If a digestive condition is suspected as the underlying cause, a gastroenterologist may recommend additional testing, such as bloodwork for celiac disease, stool studies or imaging, to identify the source of malabsorption before building a treatment plan.
When to See a Specialist
Occasional digestive discomfort is common, but persistent digestive issues paired with any of the signs above are worth a professional evaluation. A gastroenterologist can help identify whether an underlying digestive condition, such as celiac disease, inflammatory bowel disease or chronic malabsorption, is affecting magnesium and other nutrient levels, and can guide appropriate testing and treatment.
Southwoods’ Digestive Health team evaluates and manages a full range of digestive conditions, from chronic diarrhea and acid reflux to inflammatory bowel disease, as part of the broader Digestive Health and General Surgery program.
Supporting Healthy Magnesium Levels Through Diet
For most people without an underlying digestive condition, magnesium levels can be supported through food first. Magnesium-rich foods include leafy greens, legumes, nuts, seeds and whole grains.
Because individual needs vary, especially for anyone managing a digestive condition, medication or chronic illness, a personalized nutrition plan is often more effective than general guidance. You can also check out this blog post on why it’s important to consult a registered dietitian, which outlines how a dietitian can help identify nutrient gaps and build a plan around them.
For more on building a nutrient-dense diet in general, see Superfoods You Should Be Eating, and for a broader look at the vitamins and minerals your body relies on every day, don’t miss our full guide, 20 Essential Vitamins and Minerals Your Body Needs.
Talk to a Digestive Health Specialist
If ongoing digestive issues are showing up alongside fatigue, muscle cramps or other signs of magnesium deficiency, it may be time to get to the root cause. Southwoods has providers across the Mahoning Valley who can evaluate your symptoms and help determine whether an underlying condition is affecting your nutrient levels. Find a Southwoods Health physician to schedule a visit.