Extra vitamin D needed in Crohn’s

Clinical Update: Nutrition – Crohn’s disease is an incurable chronic disease that generally affects the small intestine where the absorption of vitamins and nutrients occurs.

Patients with Crohn’s disease frequently have surgery that may involve the removal of the lower part of the small intestine, which is where vitamin D tends to be maximally absorbed.
People with Crohn’s disease are also susceptible to bone-thinning, as the disease has an effect on bone metabolism. This can be accelerated by the use of steroids, which are often used in the treatment of Crohn’s disease, as these drugs elicit a bone-thinning effect. Therefore, those who have had the disease for long periods of time are more likely to develop osteoporosis.
“In Crohn’s disease, the two things that have clearly been shown to slow osteoporosis are calcium consumption and exercise,” said UCC Consultant Gastroenterologist Prof Fergus Shanahan, who operates a specialist inflammatory bowel disease clinic in Cork.
In studies conducted in collaboration with the School of Food and Nutritional Sciences at UCC under Prof Kevin Cashman, markers of bone metabolism and turnover were measured.
Crohn’s disease commonly occurs in the part of the bowel where vitamin D is absorbed and this is a serious matter for those living in the northern hemisphere, where the low absorption of vitamin D is an issue. A substantial proportion of patients with Crohn’s disease have below-normal levels of vitamin D, Prof Shanahan’s team found. It is particularly a problem during wintertime, when there is less sunlight.
“At the very minimum, any patient who goes on steroids for Crohn’s disease is given vitamin D supplements in tablet form,” said Prof Shanahan. “I also give vitamin D to people who have long-standing Crohn’s disease.”
Nowadays, Crohn’s is much better managed, which has led to an improvement in patient absorption of vitamin D. Its absorption has improved because the inflammation and disease activity has lessened due to new drug treatments. Most Crohn’s patients now spend longer periods in complete remission – whereby the intestine is healed.
In children and adolescents with Crohn’s disease, the top priority is diet – nutrition and calories are more important than drugs. “What we do is replete the patients. We restore deficiencies,” said Prof Shanahan. “We have to be planning for this long before people develop osteopenia or osteoporosis.”
Most of Prof Shanahan’s patients are on vitamin D supplements and although there can be side-effects from excess intake, it is recommended for patients whose diet is low in dairy products or low in a source of calcium.
Patients’ appearances differ greatly from that of years ago, when the classic case of a person with Crohn’s disease appeared both frail and thin. With modern treatment, this is no longer the case.