Vitamin D Status and Bone Mineral Density in African-American Children with Crohnʼs Disease

Abstract

Purpose: 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). Conclusion: 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 research should focus on how race affects vitamin D status and BMD in children with CD.