A new study published in the journal Inflammatory Bowel Diseases found that vitamin D supplementation led to improved bone mineral density and muscle power among children with inflammatory bowel disease (IBD).
IBD is a chronic inflammatory disorder affecting the digestive tract. There are two forms of IBD: Crohn’s disease and ulcerative colitis. Both conditions may result in diarrhea, abdominal pain, nutritional malabsorption and dehydration.
Of the estimated 1.4 million cases of IBD in America, approximately 10% are presented during childhood. Children frequently present with atypical signs of IBD, including mouth sores, stunted growth, fever, arthritis and anemia.
Vitamin D plays an important role in proper growth among developing children. In fact, a recent study suggested that low vitamin D status may be a major cause of short stature among children. Research has also shown that children with IBD are at a greater risk of vitamin D deficiency compared to their healthy counterparts. However, there is a lack of research regarding the relationship between IBD and musculoskeletal health among children with IBD.
Therefore, researchers conducted a prospective cohort study to evaluate whether vitamin D supplementation improved bone mineral density and muscle strength in pediatric IBD patients. A total of 55 pediatric IBD patients between the ages of 5-19 years old were included in the study. All participants received 2,000 IU vitamin D3 daily for 13 months. The participants had their 25(OH)D levels measured every 2-3 months during each follow up. The researchers observed the participants’ disease state, bone mineral density and muscle strength at baseline and completion of the study.
IBD activity was measured by indicators of inflammation from their serum analysis and a self-administered questionnaire, the pediatric ulcerative colitis activity index (PUCAI) or the pediatric Crohn’s disease activity index (PCDAI). The patients’ bone mineral densities were evaluated via computed tomography scans (CT scans). Muscle function was assessed by jumping mechanography, which measures the ground reaction forces for motion patterns.
Here is what the researchers discovered:
- At baseline, median 25(OH)D increased from 23.2 ng/ml (58 nmol/l) at baseline to 34 ng/ml (85 nmol/l) at completion of the study (p < 0.001).
- No patients experienced symptoms of vitamin D toxicity.
- Disease activity did not significantly change throughout the duration of the study (p > 0.05).
- Trabecular (porous) and cortical (dense) bone mineral density significantly improved upon completion of the study (p = 0.001 and p = 0.002, respectively).
- Maximal muscle power (combination of strength and speed) significantly increased after 13 months of supplementation (p = 0.002).
- Vitamin D supplementation was positively associated with trabecular bone mineral density and maximal muscle power (p < 0.0001).
- However, vitamin D supplementation did not significantly affect the strength-strain index (indicator of bone strength) or maximal muscle force (indicator of muscle strength).
The researchers concluded,
“We observed an improvement in bone and muscle parameters after cholecalciferol substitution in pediatric patients with IBD. Therefore, vitamin D substitution can be considered in such patients.”
The researchers acknowledged the primary limitation of the study. Without a control group to compare with, the study is unable to prove that vitamin D supplementation improves bone mineral density and muscle power. Therefore, randomized controlled trials are needed to determine whether vitamin D supplementation improves musculoskeletal health among children with IBD.
Research has shown that 2,000 IU/day will likely improve children’s vitamin D status to above 40 ng/ml; however, older children (13-19) are unlikely to reach levels above 40 ng/ml on this dosage, unless they are also receiving adequate sun exposure. We recommend 1,000 IU/25 lbs/day for children with IBD if they are unable to receive safe sun exposure. We believe sunlight offers the ideal source of vitamin D due to its independent effects on the immune system.
Sturges, M. & Cannell, JJ. Vitamin D supplementation may improve bone and muscle health among children with inflammatory bowel disease. The Vitamin D Council Blog & Newsletter, 3/2017.
Hradsky, O. et al. Supplementation with 2000 IU of Cholecalciferol Is Associated with Improvement of Trabecular Bone Mineral Density and Muscle Power in Pediatric Patients with IBD. Inflammatory Bowel Diseases, 2017.