Calcium and IBD - Getting enough without making your gut worse

If you live with Crohn's disease or ulcerative colitis, calcium can be a surprisingly difficult nutrient to get right. On one hand, people with inflammatory bowel disease are at a higher risk of low bone density and osteoporosis. On the other hand, many of the foods that contain calcium can be difficult to tolerate, particularly during a flare.

So how do you balance protecting your bones without making your gut symptoms worse?

Why calcium matters

Most people think of calcium purely as a nutrient for strong bones and teeth, and while that's certainly true, it also plays an important role in muscle contraction, nerve function and blood clotting.

For people with IBD, getting enough calcium is especially important because several factors can increase the risk of deficiency, including:

• Reduced dietary intake due to food avoidance

• Poor absorption during active inflammation

• Long-term steroid use

• Vitamin D deficiency, which reduces calcium absorption

  
  

Over time, these factors can contribute to reduced bone density if they aren't addressed.

An interesting benefit inside the gut

One of the lesser-known roles of calcium happens inside your digestive tract.

When calcium is present in the intestine, it can bind to certain fatty acids and bile acids, forming compounds that are less irritating to the lining of the bowel. Some research suggests this may help reduce direct exposure of the intestinal lining to substances that could otherwise contribute to irritation.

It's not a treatment for IBD, but it's another reminder that nutrients often do much more than we give them credit for.

Dairy isn't the enemy

One of the biggest misconceptions I hear is that everyone with IBD should avoid dairy.

The reality is far more individual.

Many people tolerate yoghurt or hard cheeses perfectly well, while others find milk triggers symptoms because of lactose intolerance rather than the dairy itself.

Cheese is often a convenient source of calcium because it's naturally low in lactose.

However, it does come with a trade-off. Many cheeses are relatively high in saturated fat and sodium, so although they can absolutely have a place in your diet, they're probably not something you'd want to rely on for the majority of your calcium intake.

As always, context matters more than labelling foods as "good" or "bad."

What about leafy greens?

Dark green vegetables such as kale, spring greens and pak choi contain calcium alongside fibre, vitamins and antioxidants. For someone in remission, these can be excellent foods to include regularly.

However, if your bowel is inflamed, or you're particularly sensitive to insoluble fibre, large amounts of raw leafy vegetables may worsen symptoms such as bloating, urgency or abdominal discomfort.

That doesn't mean they're unhealthy. It simply means timing and preparation matter.

Cooking vegetables thoroughly, blending them into soups or smoothies, or introducing them gradually can make them much easier to tolerate.

Plant-based milks can be useful too

Fortified plant milks can provide similar amounts of calcium to cow's milk and are often a great option if you don't tolerate dairy well. The one thing I'd encourage people to check is the ingredients list. Some products contain long lists of emulsifiers, gums and stabilisers. While the research is still developing, there are ongoing questions about how some food additives may influence the gut microbiome or intestinal barrier in certain individuals.

That doesn't mean you need to avoid every additive you ever see, but where possible, I generally encourage choosing products with shorter ingredient lists and fewer unnecessary extras.

The bigger picture

There isn't one perfect calcium source for everyone with IBD. Some people thrive on dairy. Others feel much better using fortified plant milks.

Some tolerate leafy greens without any issues, while others need to cook or blend them first. Rather than searching for the "best" food, focus on building a diet that provides enough calcium while also respecting your own symptoms and tolerances.

The goal isn't to force foods that make you feel unwell. It's to find the approach that allows you to nourish both your gut and the rest of your body over the long term.

If you're struggling to balance nutrition with Crohn's disease or ulcerative colitis, remember that there is rarely a one-size-fits-all answer. Building a sustainable way of eating is about understanding your own gut, not following rigid rules.