Magnesium for IBD: what's worth knowing

Could chocolate cravings be your body asking for magnesium?

Magnesium comes up a lot and there's good reason for the interest: it's one of the nutrients most likely to run low when the gut is inflamed, and it supports everything from sleep to the repair of the gut lining.

So let's walk through it gently - why it matters in IBD, who tends to run low, which form suits which situation, and whether your child needs it at all.

Mostly written with children in mind - but it holds just as true if you're an adult with, or without IBD, so do read on.

What does magnesium do, and where do we get it?

Rather a lot, as it turns out. Magnesium is a quiet workhorse, involved in over 300 reactions in the body. It helps produce energy, supports muscles and nerves, contributes to healthy blood sugar regulation, and plays an important role in sleep, a settled nervous system and normal immune function. Your body can't make it, so every bit has to come in from food.

That used to be easier than it is now. Magnesium lives in whole foods like leafy greens, nuts, seeds, beans and wholegrains, but our soils are more depleted than they once were, and a lot of processing strips it out along the way. So even without IBD in the picture, many of us probably consume less magnesium than previous generations.

Add IBD, and it can get harder still - which brings us to the next bit.

Why can it be harder to keep levels up with IBD?

A few reasons, and the gut sits at the heart of most of them:

• Frequent diarrhoea gently draws magnesium out with it.

• Small bowel Crohn's affects the very area where much of our magnesium is absorbed.

• Appetite dips and diets narrow during a flare, so less comes in.

• Inflammation, surgery and simply being unwell all add to the body's demands.

The research points the same way. A review (2022) indicated people with IBD often had lower magnesium levels than those without, with those with Crohn's disease even lower than those with ulcerative colitis.

This doesn't mean everyone with IBD is automatically low. Though the odds are clearly stacked, making magnesium one of those nutrients that's worth keeping a gentle eye on.

So how do we know if a child is low?

This is part of why magnesium is often supported within a wider plan, rather than waiting for a clear-cut "deficient" result on a test.

The difficulty is, there isn't a truly reliable everyday test for it. A standard blood (serum) magnesium test like the ones your IBD team will run, only reflects the tiny fraction - less than 1% - that circulates in the blood, and the body works hard to keep that number steady by drawing magnesium from its stores when needed. So serum levels can look perfectly normal while the body's longer-term stores are gradually becoming depleted.

In my clinic I sometimes look to a red blood cell (RBC) magnesium test, which shows the magnesium inside cells, or a Hair Tissue Mineral Analysis (HTMA) which gives a view on what the body is storing in hair. These can give a wider indication of magnesium status. If using, I tend to do this as part of a wider exploration. Often though, it's possible to gain a view from looking at diet, symptoms, medications, disease activity. And honestly, a craving for dark chocolate can also be part of the picture! No single result tells the whole story, but together they build a clearer one.

What might low magnesium feel like?

Because it's involved in so much, the signs tend to be non-specific and easily put down to other things. Some of what people notice is:

• Tiredness

• Muscle cramps or twitching

• Poor sleep

• Headaches or migraines

• Feeling wired, anxious or low

• Brain fog

• Palpitations

• Constipation (sometimes)

In a child it might show as being harder to settle at night, or a little more "on edge" than usual. Every one of these has other possible causes too, so it's a gentle prompt to look a little closer, not a diagnosis on its own.

Can magnesium help with IBD fatigue and brain fog?

If low magnesium is part of what's going on, supporting it may well help - and better sleep alone can make a noticeable difference.

But fatigue and brain fog in IBD are usually multifactorial. Ongoing inflammation, iron deficiency, low B12, poor sleep, medications and the general energy demands of living with a chronic inflammatory condition can all contribute. So it's worth checking the usual things with your IBD team, and thinking of magnesium as one supportive piece rather than the whole answer.

Will magnesium help with sleep?

Sleep is one of the big reasons magnesium comes up so often. It helps settle the nervous system and supports many of the processes involved in good sleep, so where a child is low, topping it up may help them wind down and rest a little more easily.

There's some research here too. In adults with IBD, lower magnesium has been linked with taking longer to fall asleep and sleeping for fewer hours. It's an interesting association rather than proof, and we still need more before we can say supplementing improves sleep specifically in IBD - though often my clients do feed back that they find it helpful. For now it's a useful piece of the picture.

What about headaches or aches?

I do find magnesium can sometimes help with headaches and general aches, particularly where we're trying to steer away from anti-inflammatory painkillers such as ibuprofen (often best kept to a minimum in IBD, as they can aggravate the gut). It tends to work best as part of a wider look at the simple things too, such as hydration, sleep and stress.

One important note: any recurrent or persistent pain deserves to be properly investigated rather than just managed. Do flag it with your IBD team - some aches, joint pain in particular, can be part of IBD itself and need proper assessment.

Which magnesium is best for Crohn's disease or ulcerative colitis?

There's no single winner - it depends what you're hoping to support and how the gut's behaving. Magnesium comes attached to different compounds, and that changes how well it's absorbed and how it behaves in the bowel.

Form	Often chosen for	My thoughts in IBD
Glycinate	Sleep, relaxation, muscle cramps and general supplementation	Usually my first choice where stools are loose. It's gentle on the gut and generally very well tolerated.
Citrate	Constipation and sluggish bowels	Well absorbed and useful if constipation is the issue, but it can loosen stools further, so it's rarely my first choice if diarrhoea is already present.
Malate	Muscle aches, fatigue and daytime energy	A good option where muscle discomfort or low energy are more prominent.
L-threonate	Cognitive support, focus and brain health	Interesting where brain fog is a significant issue, it crosses into the brain more readily than other forms.
Taurate	Cardiovascular support and blood pressure	More of a targeted choice than an everyday magnesium supplement.
Oxide	Constipation	Less well absorbed than the forms above. It's inexpensive, which is why it's commonly found in cheaper supplements.

For most children and adults with IBD - particularly where stools are loose - glycinate is usually where I start. It's gentle, well tolerated and suits the majority of people. If constipation is the main challenge, citrate often has the edge. Occasionally I'll use blends too.

One little tip whichever form you choose: it's the elemental magnesium on the label that tells you how much magnesium you're actually getting, so that's the figure worth looking for.

People also ask whether the magnesium in a multivitamin is enough. Usually not. Magnesium takes up a surprising amount of space, so most multivitamins can only squeeze in a small amount. They're fine for topping up a varied diet, but rarely enough if you're trying to correct a low intake.

Should I avoid citrate if there's diarrhoea?

Usually, yes. Magnesium draws water into the bowel, and the less well-absorbed forms (particularly citrate and oxide) do this the most. That's helpful for constipation, but less so when things are already loose. Glycinate tends to be the gentler choice.

Whichever form you choose, it's best to start low and build up gradually. Too much magnesium, particularly too quickly, can loosen anyone's stools.

Can magnesium citrate be used for bowel prep before a scope?

Magnesium citrate has been used as a laxative for many years, and it does feature in some bowel preparation protocols. As always, if you're thinking of varying your bowl prep, best to consult with your hospital to make sure they're happy for you to do this.

Can you get enough magnesium from food?

Sometimes, yes - and food is always a lovely place to start. Good sources include:

• Pumpkin seeds

• Almonds

• Cashews

• Dark leafy greens

• Beans and lentils

• Tofu

• Wholegrains

• Dark chocolate (you're welcome!)

The challenge is that many of these foods can feel challenging during an IBD flare. Nuts, seeds and beans are all rich in fibre, which isn't always comfortable when the gut is inflamed, and appetite is often reduced anyway. During flares, you may find smooth nut butters, cocoa in warm milk easier and sometimes a supplement simply helps bridge the gap.

Do IBD medications affect magnesium?

A couple can.

The main group to be aware of are proton pump inhibitors (PPIs) such as omeprazole and lansoprazole, commonly prescribed for reflux or stomach protection. Longer-term use (typically beyond a year) has been associated with lower magnesium levels.

Steroids such as prednisolone can also increase urinary magnesium losses.

For most people with active IBD, however, ongoing diarrhoea, reduced food intake and inflammation probably have a greater impact than medications alone.

The good news is that biologic medicines such as infliximab and adalimumab don't appear to lower magnesium directly, and neither does mesalazine or azathioprine.

Can you have too much magnesium?

A sensible question.

For most people, magnesium from food isn't something to worry about. Healthy kidneys are very good at getting rid of anything the body doesn't need.

With supplements, the first sign you've had a little too much is usually loose stools or mild tummy upset. It's the body's gentle way of saying, "That's enough."

This is exactly why it helps to start with a modest dose and increase gradually, particularly in IBD where bowel habits may already be unpredictable.

True magnesium overload is rare and is mainly a concern in people with significantly reduced kidney function or those taking very large doses.

Do I need an expensive supplement?

Not at all.

Price tells you surprisingly little.

What matters much more is:

• a reputable manufacturer

• the magnesium form is clearly stated

• the elemental magnesium content is shown

• good manufacturing standards and, where possible, third-party testing

A well-made magnesium glycinate from a trusted company is usually a far better choice than an expensive supplement with a long list of ingredients and flamboyant marketing.

Does every child with IBD need magnesium?

Magnesium is one of the supplements I recommend most often in clinic.

Between the demands of inflammation, reduced intake during flares and the challenges of absorption, it's a nutrient many children with IBD benefit from supporting, at least for a while.

That doesn't mean forever. As health improves, diets broaden and the gut settles, some children can meet their needs through food alone, while others do better with ongoing support.

As ever, it comes down to the individual - their symptoms, diet, medications, disease activity and the bigger clinical picture.

Looking deeper - magnesium's role in inflammation and repair

There's growing interest in magnesium playing a more active role in the gut. In short:

• It has a hand in immune regulation, so running low may tip things a little further towards inflammation.

• It's needed for the energy and repair that keep the gut lining renewing itself.

• It even seems to influence the gut microbiome.

Much of this is still early research and for now, primarily shown in mechanistic or animal studies, but it's a fascinating area. I'll dig into it in more detail in a future post, so make sure you're subscribed if you'd like to follow along!

A final thought

Magnesium is one of the more useful nutrients to understand in IBD. Between modern diets, the demands of inflammation and the challenges that come with Crohn's and colitis, it's one that often deserves a little attention - though always as part of the bigger picture, rather than a supplement reached for "just in case".

If you're wondering whether magnesium has a place for your child, it's exactly the kind of conversation I have with families in clinic - always alongside their medical plan, and always with the aim of helping them thrive. 💚

A few quick ones

Can I give magnesium with mesalazine or azathioprine? There are no known interactions. As a general habit, it's sensible to space supplements a couple of hours away from medicines where practical, and your pharmacist can always confirm this for your child's particular medication.

Can I give it with infliximab? Yes. Oral magnesium doesn't interfere with infliximab infusions. As always, it's worth letting your healthcare team know about any supplements you're taking.

Is glycinate better than citrate for IBD? If diarrhoea is part of the picture, usually yes. Glycinate is generally gentler on the gut, whereas citrate is more useful when constipation is the main issue.

Can magnesium make diarrhoea worse? It can. Citrate and oxide are the most likely to do so, although any form can loosen stools if the dose is too high. Start low, build gradually, and adjust according to how your gut responds.

General information, not personalised advice - always have a chat with your child's medical team before adding supplements or making changes.

References and further reading

• Gilca-Blanariu G-E, Trifan A, Ciocoiu M, et al. Magnesium - A Potential Key Player in Inflammatory Bowel Diseases? Nutrients. 2022;14(9):1914. doi:10.3390/nu14091914

• US Food and Drug Administration. Drug Safety Communication: Low magnesium levels can be associated with long-term use of proton pump inhibitor drugs (PPIs). 2011. (The UK's MHRA has issued comparable guidance on PPIs and magnesium monitoring.)