Digest IT!

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One of the most common misconceptions I encounter in my practice is the belief that a coeliac diagnosis, followed by a strict gluten-free diet, is the end of the story. In reality, for many of my clients, it is only the beginning. Nutritional deficiencies in coeliac disease are extraordinarily common — and they do not simply resolve the moment gluten is removed from the plate. Years of undiagnosed coeliac disease cause cumulative, sometimes severe damage to the small intestine, impairing the absorption of essential vitamins and minerals long before most people ever receive their diagnosis. The gluten-free diet stops the ongoing harm. But it does not automatically repay the nutritional debt that has quietly been building. That is precisely where my real work as a nutritionist begins.

Why Coeliac Disease Leaves Such a Significant Nutritional Gap

To understand why the nutritional consequences of coeliac disease run so deep, it helps to understand what is actually happening in the gut. In people with coeliac disease, gluten triggers an autoimmune response that progressively damages the villi — the tiny finger-like projections lining the small intestine that are responsible for absorbing nutrients from food. The greater the villous atrophy, the less absorptive surface area remains, and the more severely nutrient uptake is compromised.

What makes this particularly challenging is the diagnostic delay. Research published in the British Medical Journal has highlighted that the average time between symptom onset and coeliac diagnosis can stretch to several years, sometimes over a decade. During that entire period, the body is being deprived of nutrients it critically needs. By the time my clients sit across from me with a confirmed diagnosis in hand, they are frequently presenting with multiple concurrent deficiencies — not one tidy problem, but a complex web of nutritional gaps that require a systematic, personalised approach to address.

If you are in the early stages of investigating whether gluten may be affecting your health, it is worth considering a home screening tool such as the Rapid & Accurate Gluten Sensitivity Test Kit for Coeliac Disease. This is not a substitute for formal medical testing, but it can be a useful first step in identifying whether further investigation is warranted. Similarly, the 5Strands Food Intolerance Test, which analyses 658 items via a hair sample, can help identify broader food sensitivities that may be compounding gut inflammation alongside coeliac disease.

The Key Nutrients Most Affected by Coeliac Disease

When a client presents with a recent coeliac diagnosis, the first thing I do is request a comprehensive nutritional blood panel. The results are often illuminating, and they consistently point to the same cluster of deficiencies. Here are the nutrients I see depleted most frequently, and why each one matters.

Iron

Iron deficiency anaemia is one of the most classic presentations of undiagnosed coeliac disease, and one of the most frequently overlooked. Iron is primarily absorbed in the duodenum and upper jejunum — the very sections of the small intestine most severely affected by villous atrophy. I regularly see clients who have been treated for anaemia repeatedly without anyone investigating why their iron levels keep dropping. The answer, in a significant proportion of cases, is coeliac disease.

Even after going gluten-free, iron stores can take many months to replenish, particularly if intestinal healing is slow. A well-formulated supplement can make a meaningful difference during this period. I often recommend the Doctor’s Recipes Iron Supplement, which uses iron bisglycinate — a gentler, highly bioavailable form of iron that is far less likely to cause the constipation and nausea associated with standard ferrous sulphate tablets. It also includes vitamin C, B6, folate, and B12, which support absorption and red blood cell formation simultaneously. For those who prefer a larger supply, the Iron Supplement for Women & Men with Vitamins C, B6, B12 & Folate is another excellent option — gluten-free, non-GMO, and vegan-friendly.

Folate and B Vitamins

Folate, B12, and B6 are all nutrients that depend heavily on a healthy gut lining for absorption. Folate in particular is absorbed in the proximal small intestine — again, the area most affected by coeliac damage. Low folate levels contribute to megaloblastic anaemia, fatigue, and in pregnant women, significantly increased neural tube defect risk. B12 deficiency can manifest as neurological symptoms including tingling, poor concentration, and low mood — symptoms that are often attributed to other causes entirely.

Calcium and Vitamin D

Calcium absorption is impaired when the villi are damaged, and this is compounded when vitamin D levels are also low — which they almost always are in my coeliac clients. Vitamin D is essential for calcium absorption, and its deficiency in coeliac disease is well documented. The long-term consequence of untreated calcium and vitamin D deficiency is reduced bone mineral density, increasing the risk of osteopenia and osteoporosis. This is not a theoretical risk; studies have shown that adults with coeliac disease have significantly lower bone density than the general population, even after years on a gluten-free diet if supplementation is not addressed.

Zinc and Magnesium

These two minerals are less frequently discussed but consistently low in my newly diagnosed clients. Zinc plays a critical role in immune function, wound healing, and gut repair — making it particularly important during the intestinal recovery phase. Magnesium deficiency contributes to muscle cramps, poor sleep, anxiety, and fatigue, all of which are symptoms coeliac clients frequently report and which are rarely attributed to magnesium status during standard workups.

Does the Gluten-Free Diet Itself Help or Hinder Nutrient Intake?

This is a question I am asked often, and the answer is nuanced. Removing gluten allows the intestinal lining to heal, which over time does restore some absorptive capacity. However, many commercially produced gluten-free foods are notably lower in fibre, B vitamins, and iron than their conventional wheat-based counterparts, because gluten-free flours are not typically fortified in the way that standard wheat flour is in many countries. A poorly constructed gluten-free diet can actually worsen certain nutritional gaps rather than close them.

This is one reason I always encourage my clients to build their gluten-free diet around naturally gluten-free whole foods — vegetables, legumes, eggs, meat, fish, rice, quinoa, and oats (where tolerated) — rather than relying heavily on processed gluten-free alternatives. When it comes to baking at home, however, there are some genuinely excellent high-quality flour options that make the transition far more enjoyable and nutritionally viable.

Two products I regularly suggest are King Arthur Measure for Measure Gluten-Free Flour, a reliable 1:1 substitute for wheat flour that works beautifully in cookies, cakes, and muffins, and Bob’s Red Mill Gluten Free 1 to 1 Baking Flour, which is non-GMO, vegan, and kosher certified. For those who want to bake yeasted breads, bagels, or cinnamon rolls, I strongly recommend the King Arthur Gluten-Free Bread Flour, which uses a sorghum and xanthan gum blend to achieve a much better texture and rise than standard gluten-free flour in yeasted recipes. Baking your own bread means you control the ingredients — and that matters nutritionally.

For those who are still navigating dietary compliance or are concerned about accidental gluten exposure, the Gluten Detect Kit offers a practical way to test for gluten exposure via stool — a genuinely useful tool for anyone whose symptoms continue despite following a gluten-free diet and who wants to identify whether inadvertent exposure may be the cause of ongoing gut inflammation.

My Nutritionist Recommendation: A Structured Approach to Recovery

Addressing nutritional deficiencies in coeliac disease is not something that can be approached casually or left entirely to chance. In my practice, I work with newly diagnosed clients to create a structured, phased nutrition plan that prioritises three things: supporting intestinal healing, identifying and correcting specific deficiencies through food and targeted supplementation, and building long-term dietary habits that prevent deficiencies from recurring.

Here is what I recommend as a starting framework for anyone recently diagnosed with coeliac disease:

• Request a full nutritional blood panel from your GP — at minimum, check iron, ferritin, folate, B12, vitamin D, calcium, zinc, and magnesium.
• Work with a registered nutritionist or dietitian to interpret those results and build a supplementation plan tailored to your specific deficiencies, not a one-size-fits-all approach.
• Prioritise naturally gluten-free whole foods as the foundation of your diet, using quality gluten-free flours for home baking where needed.
• Support iron recovery with a stomach-friendly bisglycinate supplement such as the Doctor’s Recipes Iron Supplement or the Iron Supplement for Women & Men with Vitamins C, B6, B12 & Folate, both of which provide complementary nutrients in a gluten-free formula.
• Monitor progress with repeat blood tests every three to six months during the first year of recovery.
• Be patient with the healing process — intestinal recovery can take anywhere from six months to two years, and nutritional status improves gradually alongside it.

The gluten-free diet is essential, but it is the foundation — not the complete solution. Nutritional deficiencies in coeliac disease require active, informed management, and the sooner that work begins after diagnosis, the better the long-term outcomes for energy, bone health, immune function, and overall wellbeing. If you have recently been diagnosed and are unsure where to begin, I encourage you to book a one-to-one nutritional consultation — either with me or with a qualified practitioner near you — so that your recovery is built on a genuinely solid nutritional base.