Almost half of the children in the study with celiac disease – an intolerance to gluten in wheat, rye and barley – had suboptimal levels of vitamin D and about one quarter had suboptimal vitamin K levels, according to findings published in the European Journal of Clinical Nutrition.
Low levels of these nutrients was, in turn, associated with lower bone mineral density of the children, indicative of weaker bones, report researchers from the University of Alberta.
“Suboptimal dietary intake of vitamins D, vitamin K and calcium are common in this population, including when on a gluten-free diet,” wrote the researchers.
“Careful consideration should be given to routine supplementation of these nutrients at time of diagnosis of celiac disease.”
Over 2 million Americans suffer from celiac disease, or about 1 in 133 people, according to the National Digestive Diseases Information Clearinghouse (NDDIC).
Children who suffer from the disease are known to be at an increased risk of bone mineral density (BMD) because they cannot absorb properly certain fat-soluble vitamins like vitamin D.
In order to examine the effects of a gluten-free diet on bone and nutrient parameters, the Alberta-based scientists recruited 43 children and adolescents aged between 3 and 17 with celiac disease. At the start of the study, the participants were not consuming a gluten-free diet, and after agreeing to the study, all began consuming the diet.
Results showed that, despite a change in dietary habits, no significant improvements in various BMD measurements were observed after one year of consuming the gluten-free diet.
In addition, 23% of the children had vitamin K deficiency at the start of the study, but this was normalized after one year of the gluten-free diet.
“However, a remaining one-third of children and adolescents continued to have vitamin K intakes considerably lower than the adequate intake on the gluten-free diet and had [low] whole-body BMD scores; all pointing to suboptimal vitamin K status as a potential contributing factor to persistent poor bone health in childhood celiac disease,” wrote the researchers.
Significant numbers of the children (25%) still had suboptimal vitamin D levels after one year, said the researchers, compared with 43% at the start of the study.
“Given that all of the children had dietary intakes of calcium and vitamin D intakes well below the recommended levels, routine supplementation at time of diagnosis of celiac disease to at least the recommended daily allowance appears warranted in children and adolescents with celiac disease.”
Source: European Journal of Clinical Nutrition
Published online ahead of print, doi:10.1038/ejcn.2011.176
“Vitamin D and K status influences bone mineral density and bone accrual in children and adolescents with celiac disease”
Authors: D.R. Mager, J. Qiao, J. Turner