Dietary calcium plays a major role in maintaining normal levels of blood calcium; the effect of dietary calcium on blood calcium balance depends on adequate calcium absorption in the intestines. According to a 2010 "Molecular Nutrition and Food Research" article, diseases that cause inflammation, or irritation, of the gut, can reduce calcium absorption. These include Crohn's disease and ulcerative colitis.
Calcium Regulation
The balance of blood calcium is maintained by the thyroid and parathyroid glands. These glands are in your neck, with the parathyroids located on the back surface of the thyroid. When blood calcium dips below normal, the parathyroid glands release parathyroid hormone, which increases the breakdown of bone to release calcium into the blood. When blood calcium is elevated above normal, the thyroid glands release calcitonin, which promotes sending calcium from the blood back to bones.
Crohn's Disease
According to the National Digestive Diseases Information Clearinghouse, the incidence of Crohn's disease in males and females is nearly the same. Chron's is a serious inflammatory bowel disease, or IBD, which can affect all layers of the intestinal wall. In some cases, this can lead to perforation of the intestinal wall. According to a 2010 "Molecular Nutrition and Food Research" article, other non-vitamin D related factors could impair calcium absorption in Crohn's disease, including the severity and location of the inflammation, previous surgical history and the use of glucocorticoids or class of steriod hormones that alter glucose metabolism and suppress the immune system. Suppression of the immune system reduces the degree of inflammation seen in Crohn's disease.
Ulcerative Colitis
Ulcerative colitis is an inflammatory bowel disease that involves the formation of ulcers along extended areas of the interior abdominal wall. Unlike Crohn's disease, ulcerative colitis is less frequently associated with intestinal wall perforation, because ulcerations do not involve all layers of the intestinal wall. The inflammation associated with ulcerative colitis is typically restricted to the colon, whereas in Crohn's disease, certain portions of the small intestines are also affected. Still, ulcerative colitis can impair calcium absorption because of destruction of the inner layer of intestinal wall, which is directly involved with absorption.
Intake of Calcium in IBD
Since calcium absorption is impaired with IBD, it is reasonable to expect that increasing calcium intake would help compensate for reduced calcium absorption. However, according to "Integrative Medicine", supplementation of 100 milligrams per day, or mg/d, of calcium with 250 international units, or IUs, of vitamin D was ineffective in preventing bone density loss in patients with IBD. As a result of the ineffectivenes of calcium and vitamin D supplementation in improving bone density, calcium absorption is best addressed by preventative measures; proper management of IBD reduces inflammation and prevents destruction of the inner layer of the intestinal wall, which is involved with calcium absorption.
References
- "Molecular Nutrition and Food Research": Vitamin D-mediated Calcium Absorption in Patients with Clinically Stable Crohn's Disease; M. Kumari, et al.; 2010
- National Digestive Diseases Information Clearinghouse: Crohn's Disease
- National Digestive Diseases Information Clearinghouse: Ulcerative Colitis
- "Integrative Medicine": Calcium; David Rakel; 2007
