NEW YORK (Reuters Health) – Among patients with inflammatory bowel disease, poor vitamin D status correlates with lower bone mineral density, according to findings published in the June issue of the American Journal of Gastroenterology.

“A higher incidence of osteoporosis and fractures is a recognized complication of inflammatory bowel disease (IBD),” Dr. William D. Leslie and colleagues from the University of Manitoba, Winnipeg, Canada, write. “The role of vitamin D insufficiency in IBD-related bone disease is uncertain.”

The researchers identified adults recently diagnosed with IBD from the University of Manitoba IBD Research Registry, and measured baseline BMD and serum 25-hydroxy vitamin (25OHD) in a nested subgroup of 101 subjects.

Of the 101 subjects, only 22 (21.8%) had optimal serum 25OHD levels (75 nmol/L or greater). Six patients (5.9%) had deficient levels, 38 (37.6%) had insufficient levels, and 35 (34.7%) had marginal levels.

Higher serum 25OHD was associated with greater bone density at the lumbar spine (p < 0.01), total hip (p < 0.05), and total body (p < 0.05).

An association was observed between each SD decrease in serum 25OHD and a 3.4% reduction in spine BMD, a 2.9% reduction in total hip BMD, and a 2.0% reduction in total body BMD.

A total of 94 of the 101 subjects had repeat BMD measurements 2.3 years later. A positive correlation was observed between the gain in total body BMD in that interval and serum 25OHD (p < 0.05).

“Early optimization of vitamin D may help to prevent bone disease in inflammatory bowel disease,” Dr. Leslie commented to Reuters Health.

His group’s next step, he said, “is to see whether poor vitamin D status or the degree of activity in a patient’s inflammatory bowel disease lead to progressive loss in bone density.”

Am J Gastroenterol 2008;103:1451-1459.