It does not hurt, it cannot be seen, and it shows up on no routine blood test. Bone is nevertheless one of the organs most affected by undiagnosed celiac disease, and one of those that repairs best once the diet is in place, provided you look after it.

Why bone

Two mechanisms add up.

Malabsorption. Calcium is absorbed in the duodenum and the start of the jejunum, exactly the stretch celiac disease damages most, the same one as for iron. Vitamin D, which makes that absorption possible, is itself poorly absorbed (it is a fat-soluble vitamin, and fats get through badly in a damaged gut). To keep blood calcium up, the body draws on bone.

Inflammation. The inflammatory substances produced by active disease directly stimulate bone breakdown. A gut reacting to gluten means bone that degrades a little faster, even with enough calcium.

The result, measured in the studies: at diagnosis, a large share of adults with celiac disease, often close to half, have low bone density (osteopenia), and a minority have outright osteoporosis. Fracture risk is moderately raised. And all of it is silent: osteoporosis announces itself only through a fracture.

The scan that measures it

A bone density scan (DEXA) measures bone density, usually at the hip and the spine, with a very low dose X-ray, in a few minutes, with no preparation. It gives a score compared with a reference: normal, osteopenia, osteoporosis.

In adults, most guidelines suggest one at diagnosis of celiac disease or within the following year, routinely in some protocols, based on risk factors in others: over 30, late diagnosis, marked deficiencies, menopause, previous fracture, low body weight. It serves as a starting point, and is repeated one to two years later to measure recovery.

In children and teenagers it is not routine: their bone rebuilds quickly and completely on the diet. It is considered in severe or late-diagnosed cases.

What the diet repairs

This is the good news of the article, and it is solid. A strict gluten-free diet is the treatment for celiac bone. As the lining heals (the timelines are here), calcium and vitamin D absorption resumes, inflammation dies down, and bone density climbs noticeably from the first year, by several percent, which is a lot for bone. The improvement continues over several years.

In children and teenagers, recovery is usually complete: they reach the same peak bone mass as everyone else, provided the diet is strict through the growing years. In adults diagnosed late, in their forties or fifties, it can stay partial, because bone has less capacity to rebuild. For them, everything else counts most.

Children and teenagers

Recovery usually complete

  • Same peak bone mass as everyone else
  • Provided the diet is strict through the growing years

Adults diagnosed late

Recovery can stay partial

  • In their forties or fifties
  • Bone has less capacity to rebuild
  • Calcium, vitamin D and exercise count most

What to add

The diet does most of the work, not all of it.

  • Calcium, from food first: dairy (if lactose is tolerated, or in lactose-free form), cheese, calcium-rich mineral water, green vegetables (cabbage, broccoli), sardines with the bones, almonds, calcium-set tofu. The target for an adult is in the region of 1,000 to 1,200 mg a day; a supplement makes up the difference if food does not get you there.
  • Vitamin D. Deficiency is very common at diagnosis, and it is rarely corrected by food alone: a supplement is almost always prescribed, dosed on your blood results, and often continued. Sunshine helps, less so in winter.
  • Physical activity, especially the kind that loads bone: walking, running, stairs, strength training. Bone strengthens under load; it weakens at rest. It is one of the few pieces of health advice that applies to everyone and costs nothing.
  • Avoid what damages bone: smoking, excess alcohol, being underweight.
  • Osteoporosis medication (bisphosphonates and others) is a conversation to have with your doctor when density is clearly low or there has been a fracture; for most people with celiac disease, the diet, calcium and vitamin D are enough, and the picture is reassessed at the next scan.

In short

  • Celiac disease weakens bone through poor absorption of calcium and vitamin D, and through inflammation; it is silent.
  • At diagnosis, a large share of adults have low density: a bone density scan for adults, at diagnosis or within the year.
  • A strict diet is the treatment: density climbs from the first year, completely in children, partially in adults diagnosed late.
  • Calcium from food (1,000 to 1,200 mg), vitamin D almost always supplemented, weight-bearing activity.
  • A follow-up scan at one to two years to measure recovery.

Sources

  • Heikkilä K., Pearce J., Mäki M., Kaukinen K. Celiac disease and bone fractures: a systematic review and meta-analysis. Journal of Clinical Endocrinology & Metabolism, 2015; 100(1): 25-34. Fracture risk around 30% higher in people with celiac disease.
  • Zanchetta M. B., Longobardi V., Bai J. C. Bone and celiac disease. Current Osteoporosis Reports, 2016; 14(2): 43-48. Mechanisms, prevalence of osteopenia and osteoporosis at diagnosis, recovery on the diet.
  • Ludvigsson J. F. et al. Diagnosis and management of adult coeliac disease: guidelines from the British Society of Gastroenterology. Gut, 2014; 63(8): 1210-1228. Indications for bone density scanning and recommended calcium intakes.
  • Al-Toma A. et al. ESsCD guideline for coeliac disease and other gluten-related disorders. United European Gastroenterology Journal, 2019; 7(5): 583-613.
  • Mora S. et al. Reversal of low bone density with a gluten-free diet in children and adolescents with celiac disease. American Journal of Clinical Nutrition, 1998; 67(3): 477-481. Complete recovery of bone density in children on the diet.

This information does not replace medical advice. Whether to order a bone density scan, the doses of calcium and vitamin D, and any osteoporosis treatment are decided with your doctor, based on your results.