People with ulcerative colitis (UC) may have low magnesium levels due to their symptoms. Supplementing magnesium and eating magnesium-rich foods may help those with UC avoid a deficiency in this nutrient.

Magnesium is an essential mineral necessary for many bodily functions. It helps control muscles and nerves, preserve bone health, and maintain heart rhythm, among other functions.

Low magnesium levels may have adverse health effects.

This article explains why people with UC may become deficient in magnesium and how doctors diagnose it. It also explores the possible consequences of low magnesium and lists other supplements that may benefit those with UC.

A note about sex and gender

Sex and gender exist on spectrums. This article will use the terms “male,” “female,” or both to refer to sex assigned at birth. Learn more.

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UC is a form of inflammatory bowel disease (IBD). It affects the gut’s ability to digest food properly and absorb essential nutrients, which can result in malnutrition.

The Crohn’s and Colitis Foundation advises that symptoms such as diarrhea may also contribute to nutrient deficiencies, such as low magnesium, dehydration, and electrolyte imbalances. Flares of symptoms, certain surgical treatments, and complications of UC may make it difficult for some people with the condition to get enough nutrients from food alone.

Furthermore, someone with UC may restrict the foods they eat to avoid foods that trigger their symptoms. Doing so may further lower nutrient levels. A restrictive or limited diet may not include all the essential vitamins or minerals key to a balanced diet. Therefore, someone with UC may have lower magnesium levels or a deficiency according to their diet.

Research included in an older 2017 article shows that 18% to 62%Trusted Source of people with UC have malnutrition due to an imbalance in dietary intake.

A 2022 studyTrusted Source found that individuals with IBD have lower magnesium levels than those without the condition.

The researchers carried out a hair mineral analysis and suggested that magnesium either plays a primary role in the development of the disease or results from IBD symptoms. The same study linked magnesium supplementation with improved UC disease activity and sleep quality.

Further resources

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The authors of a 2022 study noted that magnesium deficiency might have the following effects on people with IBD:

The National Institutes of Health (NIH)Trusted Source suggests that low magnesium levels may also contribute to the following conditions:

A person with UC needs to consult a doctor if they are experiencing any of the above symptoms.

The following foods are good sourcesTrusted Source of magnesium:

Tap, mineral, and bottled water can also provide magnesium. However, the amount of magnesium in water varies by source and brand.

Magnesium supplements are available in a variety of forms, including:

  • magnesium oxide
  • magnesium chloride
  • magnesium citrate
  • magnesium glycinate
  • magnesium lactate
  • magnesium aspartate

The NIHTrusted Source advises that people may absorb the following forms more efficiently, and they may be more available in the body:

  • aspartate
  • citrate
  • lactate
  • chloride

Additionally, older researchTrusted Source notes that very high doses of zinc from supplements may interfere with magnesium absorption in males. Additionally, research from 2004Trusted Source found that a moderately high intake of zinc decreased magnesium balance in postmenopausal females.

People can buy magnesium supplements in the form of powders, liquids, or tablets.

Research in a 2018 reviewTrusted Source indicates that 60% of adults do not achieve the dietary intake of magnesium that experts recommend. However, the review suggests that the available tests for magnesium status are variable in their results, so diagnosing a deficiency is challenging.

The absorption and metabolism of magnesium in the body also make it difficult to tell whether a person has enough of this mineral.

A doctor may test a person’s blood or urine to check for a magnesium deficiency. They will also ask them whether they have been experiencing any symptomsTrusted Source that suggest a deficiency. These include:

Anyone with a magnesium deficiency needs to ask a doctor or nutritionist to assess whether they have other nutrient deficiencies.

A 2024 studyTrusted Source indicates that people with IBD commonly have the following deficiencies:

Doctors may recommend additional supplementation or advise the person to eat more of certain types of foods.

In addition, healthcare professionals may recommendTrusted Source that people with IBD follow an anti-inflammatory or Mediterranean diet. These eating plans contain a suitable quantity of the nutrients that a person needs.

A person with ulcerative colitis (UC) may be deficient in magnesium due to symptoms such as diarrhea, a restricted diet, or other complications. Low magnesium levels may further affect gut health and cause additional health problems, such as osteoporosis or fatigue.

Doctors will test someone’s magnesium levels and ask about symptoms of deficiency. Many foods contain magnesium, but a doctor may sometimes recommend taking a supplement.