Osteopenia and the progression to osteoporosis is a well-known complication of gastrointestinal disease.¹ Disorders of the gastrointestinal tract are often overlooked as a cause of reduced bone density, and subsequently osteoporosis, which is generally considered a disease of the elderly, may present at any age when gastrointestinal disease is present.²

The absorption of calcium and other macro- and micro elements essential for bone metabolism takes place in the gastrointestinal tract. Hence, any degree of malabsorption or maldigestion due to intestinal insufficiency (for example, as seen in coeliac disease, post gastrectomy, short gut, pancreatic insufficiency, Crohn’s disease and ulcerative colitis) may negatively influence bone metabolism and increase the risk for developing osteoporosis (see Table 1).^2,3 Recent data have also suggested that osteoporosis and fractures may be enhanced in patients with irritable bowel syndrome (IBS).⁴

Table 1. The incidence of osteoporosis and the relative risk of fractures in select gastrointestinal diseases.¹

Many factors effect bone metabolism, and increasing evidence highlights the central role that inflammation plays in bone health.5 Inflammation is characterised by the production of cytokines, which is associated with increased bone resorption and reduced bone formation. As such, bone loss and increased fracture risk is to be expected in all processes associated with chronic inflammation.⁶  Inflammatory cytokines such as serum IL-1β, tumor necrosis factor (TNF)-α, IL1, IL-6, IL-11, IL-15 and IL-17 are increased in IBD and in CD patients, with direct effects on bone turnover.^2,5

The minimum daily calcium dose necessary to prevent a negative balance is 1000 mg of elemental calcium for men and premenopausal women, and 1200–1500 mg for postmenopausal women and men older than 60 years. Inadequate calcium intake is present in one third of IBD patients and represents an easily reversible risk factor for osteoporosis via dietary modification and/or supplementation.⁷

Multiple studies have identified a high prevalence of vitamin D deficiency in patients suffering from gastrointestinal disease.^6,8 The role of vitamin D is crucial in bone mineralization.9 Vitamin D deficiency reduces intestinal calcium and phosphate absorption and induces secondary hyperparathyroidism. Consequently, osteoclastogenesis is stimulated, bone turnover is increased, and osteopenia and osteoporosis is promoted.6 Observational studies also correlate low vitamin K levels with inflammatory bowel disease activity as well as its involvement in the pathogenesis of osteoporosis in these patients.^8,10

Early prevention and treatment are essential in the appropriate management of osteoporosis yet, many people are unaware of the serious consequences of osteoporosis, including increased morbidity and mortality, until it manifests in the form of fracture. As such, one of the key goals in managing gastrointestinal-related osteoporosis is to ensure that the patient is receiving adequate nutritional support.²

These findings highlight the importance of additional supplementation in cases of intestinal insufficiency due to compromised nutrient absorption, along with the fact that the standard RDIs are rarely met with diet alone.^2,11

Practitioners should therefore consider the following treatment approaches:

• Consider inflammation as a factor and review dietary and lifestyle contributing factors.
  • Encourage a diet rich in anti-inflammatory foods such as oily fish, fruits, vegetables, nuts and seeds and limit pro-inflammatory foods such as sugary drinks, refined carbohydrates, trans fats and processed meats.
  • Supplementation with Curcumin can act as a potent adjunct to dietary changes.
• Introduce a gut health protocol to optimise healthy gastrointestinal function.
  • Ensure adequate gastric acid and enzymatic production with betaine hydrochloride, pancreatic or plant-based enzymes and herbs such as gentian, dandelion root and ginger.
  • Optimise nutrient absorption by supporting healthy intestinal epithelial function with glutamine, vitamin A, vitamin D and zinc. 
• Educate patients on key diet and lifestyle factors that promote bone health.
  • Regular physical exercise- 3-5 times per week, including some form of weight bearing exercise
  • Spending more time in the sun to optimise Vitamin D3 exposure
  • Cessation of smoking, and the avoidance of excessive alcohol intake.
• Supplement at risk groups with a combination of evidence-based bone health nutrients.
  • This may include bioavailable calcium, vitamin D3, vitamin K2 and key cofactors including magnesium, manganese, zinc and boron.

References

1. Oh, H.J., et al., Osteoporosis and Osteoporotic Fractures in Gastrointestinal Disease. Journal of bone metabolism, 2018. 25(4): p. 213-217.
2. Katz, S. and S. Weinerman, Osteoporosis and gastrointestinal disease. Gastroenterology & hepatology, 2010. 6(8): p. 506-517.
3. Nygaard, L., et al., Osteoporosis in patients with intestinal insufficiency and intestinal failure: Prevalence and clinical risk factors. Clin Nutr, 2018. 37(5): p. 1654-1660.
4. Bertoldi Franco, C., Osteoporosis in gastrointestinal diseases. Translational Gastrointestinal Cancer, 2014. 4(1): p. 57-68.
5. Lima, C.A., et al., Risk factors for osteoporosis in inflammatory bowel disease patients. World journal of gastrointestinal pathophysiology, 2015. 6(4): p. 210-218.
6. Krela-Kazmierczak, I., et al., Osteoporosis in Gastrointestinal Diseases. Adv Clin Exp Med, 2016. 25(1): p. 185-90.
7. Vernia, P., et al., Dietary calcium intake in patients with inflammatory bowel disease. Journal of Crohn's and Colitis, 2014. 8(4): p. 312-317.
8. Masri, O.A., J.M. Chalhoub, and A.I. Sharara, Role of vitamins in gastrointestinal diseases. World J Gastroenterol, 2015. 21(17): p. 5191-209.
9. Goltzman, D., Functions of vitamin D in bone. Histochem Cell Biol, 2018. 149(4): p. 305-312.
10. Kuwabara, A., et al., High prevalence of vitamin K and D deficiency and decreased BMD in inflammatory bowel disease. Osteoporos Int, 2009. 20(6): p. 935-42.
11. Fulgoni, V.L., 3rd, et al., Foods, fortificants, and supplements: Where do Americans get their nutrients? The Journal of Nutrition, 2011. 141(10): p. 1847-1854.