In one study, 43 children with celiac disease, aged 3 to 17, agreed to follow a gluten free diet. At the start, 43 percent were low in vitamin D and 25 percent were low in vitamin K, with a direct link to lower bone mineral density (BMD) scores.
After one year, BMD scores had not changed. One-third of the children were still not getting enough vitamin K on the gluten free diet, and all the children were getting too little calcium and vitamin D.
Study authors said children with celiac disease should supplement at least the recommended daily allowance for calcium, vitamin D and vitamin K.