Vitamin D and K status influences bone mineral density and bone accrual in children and adolescents with celiac disease

Abstract

Children with celiac disease (CD) are at risk for decreased bone mineral density (BMD) because of fat-soluble vitamin malabsorption, inflammation and/or under-nutrition. The study objective was to determine the interrelationships between vitamin K/D status and lifestyle variables on BMD in children and adolescents with CD at diagnosis and after 1 year on the gluten-free diet (GFD). Children and adolescents aged 3-17 years with biopsy proven CD at diagnosis and after 1 year on the GFD were studied. BMD was measured using dual-energy X-ray absorptiometry. Relevant variables included: anthropometrics, vitamin D/K status, diet, physical activity and sunlight exposure. Whole-body and lumbar-spine BMD-z scores were low (< or = -1) at diagnosis (10-20%) and after 1 year (30-32%) in the children, independent of symptoms. Whole-body BMD-z scores (-0.55±0.7 versus 0.72±1.5) and serum levels of 25(OH) vitamin D (90.3±24.8 versus 70.5±19.8 nmol/l) were significantly lower in older children (>10 years) when compared with younger children (< or =10 years) (P<0.001). Forty-three percent had suboptimal vitamin D status (25(OH)-vitamin D <75 nmol/l) at diagnosis; resolving in nearly half after 1 year on the GFD. Twenty-five percent had suboptimal vitamin K status at diagnosis; all resolved after 1 year. Children and adolescents with CD are at risk for suboptimal bone health at time of diagnosis and after 1 year on GFD; likely due in part to suboptimal vitamin D/K status. Therapeutic strategies aimed at optimizing vitamin K/D intake may contribute to improved BMD in children with CD.