Diseases of the gastrointestinal system can affect nutrient absorption, putting individuals at risk of osteoporosis and fragility fractures. It is important that individuals with the following disorders have their nutrient status checked.
IBD refers to a number of diseases, which are characterized by inflammation of the bowel. The most common of such disorders are Crohn’s disease and ulcerative colitis. Symptoms of these disorders tend to occur intermittently, and include diarrhoea, abdominal cramps and pains, fever and weight loss.
A number of factors predispose sufferers to be at increased risk of bone loss and fragility fractures:
- Poor food intake and nutritional status
- Poor absorption of nutrients by the damaged intestine (including calcium, vitamin D, protein and calories)
- Surgery to remove parts of the intestine
- Treatment with glucocorticoid medications to reduce the inflammation
- Hormonal modifications induced by the gastrointestinal disease
- Release of cytokines as part of the inflammatory process, which increase the loss of calcium from bone
As compared to age- and sex-matched controls, IBD sufferers have significantly higher rates of osteoporosis (approx. 30%), with those requiring hospitalization for IBD having considerably increased risk for osteoporosis and fractures Tsai, M.S., et al., Risks and predictors of osteoporosis in patients with inflammatory bowel diseases in an Asian population: a nationwide population-based cohort study. Int J Clin Pract, 2015. 69(2): p. 235-41.
Osteoporosis prevention measures need to be included in the overall care strategy for patients with these disorders, including ensuring an adequate calcium and vitamin D intake either through diet or supplements, and regular weight-bearing exercise. Osteoporosis medications may be recommended for some patients, for example older patients taking long-term glucocorticoid therapy and those with prior fragility fractures.
Coeliac disease (CD) is a genetically mediated autoimmune disease characterized by intolerance to gluten (a protein group) found in wheat, rye and barley. It is a relatively common disorder thought to affect about 0.5–1% of the population. Those affected suffer damage to the villi, the tiny finger-like protrusions lining the surface of the intestine that are involved in the absorption of nutrients from food. Symptoms include diarrhoea, weight loss, anaemia, fatigue, muscle cramps and nutritional deficiencies. The disorder has to be controlled by strict adherence to a gluten-free diet.
People with CD may be at increased risk of osteoporosis if the disorder goes undiagnosed or is poorly controlled, due to inadequate nutrient absorption from food (including calcium and vitamin D), sometimes leading to frank malnutrition. Rates of CD are commonly found to be higher among patients with osteoporosis than those without osteoporosis. Consequently, as CD can sometimes have no symptoms, doctors may test for the condition when an individual is found to be osteoporotic. It may also be ‘discovered’ when a patient who is vitamin D-deficient shows no response if given a large therapeutic dose of vitamin D.
Clinical guidelines relating to the prevention and treatment of osteoporosis in coeliac disease are available, including in Canada, Germany, UK and the United States.
In 2014, the British Society of Gastroenterology (BSG) published guidelines on the diagnosis and management of adult Ludvigsson, J.F., et al., Diagnosis and management of adult coeliac disease: guidelines from the British Society of Gastroenterology. Gut, 2014. 63(8): p. 1210-28.
. Recommendations relating to bone health include:
- Bone mineral density should be measured after one year of diet in patients who have additional risk factors for osteoporosis or if over the age of 55 years
- Adult patients with CD should have a calcium intake of at least 1,000 mg per day
- A gluten-free diet is the core management strategy for prevention of osteoporosis
Lactose maldigestion results from a deficiency in the enzyme lactase, produced in the small intestine, which is responsible for breaking down lactose into simpler sugars, which are then absorbed by the body. The term lactose intolerance refers to the abdominal symptoms (e.g., cramps, bloating) resulting from the inability to digest lactose. The prevalence of lactose intolerance varies significantly between races and as a function of age. A systematic literature review has reported Wilt, T.J., et al., Lactose intolerance and health. Evid Rep Technol Assess (Full Rep), 2010(192): p. 1-410.
that the prevalence of lactose intolerance is very low in children and remained low into adulthood among individuals of Northern European descent. Prevalence of lactose intolerance in African American, Hispanic, Asian, and American Indian populations may be 50% higher in late childhood and adulthood.
In 2010, the U.S. National Institutes of Health (NIH) published a consensus development conference statement on lactose intolerance and health Suchy, F.J., et al., NIH consensus development conference statement: Lactose intolerance and health. NIH Consens State Sci Statements, 2010. 27(2): p. 1-27.
. Key components of the statement included:
- The majority of people with lactose malabsorption do not have clinical lactose intolerance. Many individuals who think they are lactose intolerant are not lactose malabsorbers.
- Many individuals with real or perceived lactose intolerance avoid dairy foods and thus ingest inadequate amounts of calcium and vitamin D, which may predispose them to decreased bone accrual, osteoporosis, and other adverse health outcomes. In most cases, individuals do not need to eliminate dairy consumption completely.
- Evidence-based dietary approaches with and without dairy foods and supplementation strategies are needed to ensure appropriate consumption of calcium and other nutrients in lactose-intolerant individuals.
Being lactose intolerant does not necessarily preclude all dairy products from the diet. Yoghurt with live cultures can often be tolerated, because the bacteria in the cultures produce the enzyme lactase, and some hard cheeses contain only negligible amounts of lactose. Some people with the disorder can still drink small quantities of milk without suffering any symptoms, and, in some countries, lactose-reduced milks are available.
Another alternative is to take lactase tablets or drops along with dairy foods. As well, other foods and drinks can provide good sources of calcium, such as green leafy vegetables, nuts, canned fish with soft, edible bones such as salmon and sardines, calcium-fortified beverages and calcium-rich mineral waters.
If adequate calcium is not possible through the diet, the use of supplements should be considered.
Anorexia nervosa is an eating disorder associated with low body weight and irrational fear of weight gain. Among the many serious physical consequences of anorexia nervosa is low bone mineral density and impaired bone structure and strength.
On average, the onset of anorexia nervosa is at around the age of 16 to 17, with the number of younger children affected continuing to rise National Health Service (NHS): Overview - Anorexia Nervosa. [Accessed 15.02.2019];
. This is a concern for bone health because childhood and adolescence are critical periods for bone development. Adolescents with anorexia nervosa have lower BMD than normal-weight adolescents of comparable age and maturity and have lower rates of bone accrual. Individuals with a past history of anorexia have a two to threefold increased risk of bone fracture Misra, M., N.H. Golden, and D.K. Katzman, State of the art systematic review of bone disease in anorexia nervosa. Int J Eat Disord, 2016. 49(3): p. 276-92.
Misra, M., et al., Bone metabolism in adolescent boys with anorexia nervosa. J Clin Endocrinol Metab, 2008. 93(8): p. 3029-36.
Misra, M., et al., Weight gain and restoration of menses as predictors of bone mineral density change in adolescent girls with anorexia nervosa-1. J Clin Endocrinol Metab, 2008. 93(4): p. 1231-7.
The extent of anorexia nervosa’s impact on bone health depends on many factors, including its duration, the severity of the disease, and how early it occurs. Restoring weight and hormones to normal is the cornerstone of treatment for low bone mineral density in anorexia. In young women this goal will help to restore monthly periods. Dieticians will seek to normalize eating behaviour, with attention to nutritional status. Calcium and vitamin D are extremely important for bone development in young people and supplements may be advised to ensure adequate intake. See Anorexia Fact Sheet.