When my daughter was first diagnosed with celiac disease, I remember sitting in my kitchen late at night, surrounded by stacks of medical journals and printouts from reputable health sites, trying to wrap my head around what was actually happening inside her body. I knew gluten was the problem-but why? And more importantly, how was it affecting her ability to get the nutrients she needed to grow and thrive?

What I learned changed the way I think about food, digestion, and healing. Let me walk you through it in a way I wish someone had explained to me back then.

The Tiny Heroes of Digestion

Think of your small intestine as a long, winding garden hose-about 20 feet long in adults. Its inner surface isn't smooth like the inside of a pipe. Instead, it's lined with millions of tiny, finger-like projections called villi. If you could zoom in even closer, you'd see that each villus is covered in even tinier projections called microvilli. Together, they form what's known as the "brush border."

Here's the key: these villi and microvilli dramatically increase the surface area of your small intestine. In fact, if you could flatten them all out, the surface area would be roughly the size of a tennis court. That massive surface is what allows your body to absorb nutrients from the food you eat-vitamins, minerals, fats, proteins, and carbohydrates all pass through this intricate landscape into your bloodstream.

What Celiac Disease Does to That Landscape

When someone with celiac disease eats gluten-a protein found in wheat, barley, and rye-their immune system launches an attack. But instead of attacking the gluten itself, the immune system mistakenly targets the villi in the small intestine. Over time, those beautiful, healthy villi become flattened, inflamed, and damaged.

This process is called villous atrophy, and it's the core of what makes celiac disease so disruptive. Imagine that tennis court of absorption surface shrinking down to the size of a ping-pong table. Suddenly, your body has far less capacity to pull nutrients out of the food you eat.

The Nutrient Absorption Breakdown

Not all nutrients are affected equally. Here's what happens with the major players:

• Fat and Fat-Soluble Vitamins (A, D, E, K): These are often the first to be compromised. Fats require bile acids and healthy villi for proper absorption. When the villi are damaged, undigested fats can pass through the digestive tract, leading to greasy, pale stools. More importantly, your body struggles to absorb vitamins A, D, E, and K-which are crucial for everything from bone health to immune function to blood clotting.
• Iron: Iron deficiency is incredibly common in newly diagnosed celiac disease. Iron is absorbed primarily in the upper part of the small intestine-exactly where the damage tends to be worst. This is why many people with undiagnosed celiac disease experience fatigue, weakness, and even anemia.
• Calcium and Vitamin D: These two work together for bone health. Damaged villi mean less calcium absorption, and without enough vitamin D (which is also poorly absorbed), your body can't use what little calcium it does get. This is why osteoporosis is a real concern for those with untreated celiac disease.
• B Vitamins: Folate (B9) and B12 are absorbed in specific sections of the small intestine. When those sections are damaged, deficiency can lead to fatigue, neurological symptoms, and even mood changes.
• Zinc and Magnesium: These minerals are essential for immune function, wound healing, and energy production. Their absorption is also compromised in damaged intestines.

Why Symptoms Vary So Much

Here's something that surprised me: two people with celiac disease can have vastly different symptoms-or no obvious digestive symptoms at all. That's because the extent and location of villous damage varies from person to person. Some might have severe damage in the upper small intestine (affecting iron and calcium absorption), while others might have damage spread more evenly throughout.

This is why some people present with anemia, others with bone pain, and still others with neurological issues like brain fog or tingling in their hands and feet. The nutrient deficiencies tell the story of where the damage is.

The Good News: Healing Is Possible

Here's what gave me hope during those late-night research sessions: when gluten is completely removed from the diet, the villi can heal. It's not instant-for adults, it can take months to a couple of years for the intestine to fully recover. But children often heal faster, sometimes within six months to a year.

That healing is why a strict gluten-free diet is non-negotiable. Every time gluten enters the body, the immune response starts again, damaging those precious villi and setting back the clock on nutrient absorption.

What This Means for Everyday Eating

For our family, understanding this process changed how we approached meals. We focused on nutrient-dense foods that would be easy to absorb even while the gut was healing-things like bone broth (rich in easily absorbable minerals), cooked vegetables (gentler on the digestive system), and healthy fats from sources like avocado and olive oil.

We also learned to be patient with our daughter's body. Even after she stopped eating gluten, it took time for her nutrient levels to normalize. We worked with her healthcare provider to monitor key markers like iron, vitamin D, and B12.

A Note on Clean Eating

This is where I've come to appreciate what "clean" really means-not just free from gluten, but full of ingredients that support healing. When I discovered Clean Monday Meals, I was relieved to find organic ramen noodles paired with clean seasoning. For us, that means no hidden gluten, no artificial additives, and ingredients I can actually pronounce. It's comfort food that doesn't compromise on the careful eating that celiac disease demands.

The small intestine is remarkable in its ability to heal when given the chance. Understanding how celiac disease affects nutrient absorption helped me become a better advocate for my daughter-and a more thoughtful cook for our entire family. Knowledge, in this case, truly is power. And for anyone navigating this journey, that knowledge is the first step toward healing.