Celiac.com 12/24/2015 - Laboratory tests for hemoglobin, ferritin, calcium, folate, vitamin B12, vitamin D, and thyroid function are regularly ordered in children with celiac disease, despite sufficient evidence for their necessity. To determine the frequency of nutritional deficiencies and levels of thyroid dysfunction in children with celiac disease, researches conducted a study that examined children before and after the initiation of a gluten-free diet.
For their study, the team evaluated test results for hemoglobin, ferritin, folate, vitamin B12, calcium, vitamin D (25[OH]D), free thyroxin, and thyroid stimulating hormone of children with celiac disease regularly seen at the Leiden University Medical Center between 2009 and 2014. The team used laboratory reference ranges to define abnormal results. For statistical analysis, they used Pearson χ2 test for trend, unpaired t test, and 1-way ANOVA.
Their results for 182 children evaluated, showed 119 were newly diagnosed. About 17% of results were missing for any given year, due to incomplete blood results.
The most common deficiencies at the time of celiac diagnosis were iron deficiency, found in 28% of celiac patients, vitamin D deficiencies in 27%, and folate deficiency, in 14%. They also saw iron deficiency anemia in 9%, and vitamin B12 deficiency in 1% of celiac patients. They saw no hypocalcemia or thyroid dysfunction.
At follow-up, they observed iron deficiency, iron deficiency anemia, and folate and vitamin D deficiency 8%, 2%, 3%, and 25% of patients, respectively. They found no vitamin B12 deficiency, hypocalcemia, and thyroid disease.
From these results, the team concluded that complementary blood investigations are relevant at the time of celiac diagnosis, but have little follow-up use, once the patients adopt a gluten-free diet. They recommend that such tests be conducted only if there is a clear physical issue, such as fatigue or abnormal growth.