Vitamin D Status and Bone Mineral Density in African American Children With Crohn Disease

Abstract

Background Vitamin D deficiency and low bone mineral density (BMD) are complications of inflammatory bowel disease. Vitamin D deficiency is more prevalent among individuals of color compared to Caucasians. There is little data comparing differences in serum 25-hydroxyvitamin D (25OHD) concentrations and BMD between African American and Caucasian children with Crohn’s Disease (CD). Methods We compared serum 25OHD concentrations of African American children with CD (n=52) to Caucasian children with CD (n=64) and healthy African American controls (n=40). We also analyzed BMD using dual energy x-ray absorptiometry (DXA) results from our pediatric CD population. Results African American children with CD had lower serum 25OHD concentrations [16.1 (14.5-17.9, 95%CI) ng/mL] than Caucasians with CD [22.3 (20.2-24.6, 95%CI) ng/mL; p<0.001]. African Americans with CD and controls exhibited similar serum 25OHD concentration [16.1 (14.5-17.9, 95%CI) vs 16.3 (14.4-18.4, 95%CI) ng/mL; NS]. African Americans with CD exhibited no difference in serum 25OHD concentration when controlling for seasonality, disease severity and surgical history, though serum 25OHD concentration was significantly decreased in overweight children (BMI≥85%, p =0.003). Multiple regression analysis demonstrated that obese African American females with CD had the lowest serum 25OHD concentrations [9.6 (6.8-13.5, 95%CI) ng/mL]. BMD was comparable between African American and Caucasian children with CD (Z score −0.4 ± 0.9 vs −0.7 ± 1.2; NS). Conclusions African American children with CD are more likely to have vitamin D deficiency compared to Caucasian with CD, but have similar BMD. CD disease severity and history of surgery do not affect serum 25OHD concentrations among African American children with CD. African American children have low serum 25OHD concentrations, independent of CD, compared to Caucasian children. Future should research should focus on how race affects vitamin D status and BMD in children with CD.

Pilot Study Evaluating Efficacy of 2 Regimens for Hypovitaminosis D Repletion in Pediatric Inflammatory Bowel Disease

“…Our group has previously demonstrated that African-Americans tend to have low vitamin D status or vitamin D deficiency regardless of their IBD disease status [25]. Overall bone health appears to be impacted by IBD and vitamin D status in Caucasians, whereas African-Americans’ bone health may not be affected by the presence of IBD or by African-Americans’ overall vitamin D status.…”

Association between 25(OH)D Level, Ultraviolet Exposure, Geographical Location, and Inflammatory Bowel Disease Activity: A Systematic Review and Meta-Analysis

“…The 21 studies included 5 studies conducted in Europe, 9 in North America, 4 in Asia, 1 in Brazil, and 2 in Australia. Our study included 13 studies investigating the association between CD and vitamin D levels [ 17 , 18 , 20 – 30 ]. Of them, eight studies also referred to the relationship between UC and vitamin D levels[ 17 , 20 , 21 , 23 , 24 , 27 , 29 , 30 ].…”

“…The cut-off level for 25(OH)D deficiency was defined as less than 50 nmol/L[ 16 ]. For two studies[ 17 , 18 ] that provided 95% confidence intervals (CIs) instead of SDs, we obtained a final SD using a reduction formula[ 19 ]. Because of the different characteristics between CD and UC, we analyzed them independently.…”

“…To correct for bias in a small sample size, we used a random effects model. In our study, three studies involving pediatric participants were included[ 18 , 20 , 21 ]. Considering the possible differences in vitamin D levels between children and adults, we also opted to stratify our analyses in pediatric and adult participants.…”

The role of vitamin D in Crohn’s disease: Literature review

“…Some researchers suggest that there is a relationship between vitamin D level and bone mineral density in adults while others do not find such a correlation. 29,30 Krela-Kaźmierczak et al studied the association between the serum levels of interleukins (IL-13, IL-4, IL-17, IL-1β), osteoprotegerin and s-RANKL proteins in patients with CD and decreased BMD. The results of their study showed that IL-13, IL-1β, and IL-4 seem to be connected with the pathology of low BMD in CD.…”