Hypocalcemia and Vitamin D Deficiency in Children with Inflammatory Bowel Diseases and Lactose Intolerance

Background: A diet restricted in dairy products can cause calcium and vitamin D deficiency and, secondarily, lead to malnutrition and low bone mass. The aim of the study was to determine the incidence hypocalcemia and vitamin D deficiency in children with inflammatory bowel diseases and lactose intolerance (LI). Material and Methods: A total of 107 patients were enrolled to the study (mean age 14.07 ± 3.58 years; 46.7% boys): 43 with Crohn’s disease (CD), 31 with ulcerative colitis (UC), and 33 with functional abdominal pain (AP-FGID). Hydrogen breath test with lactose and laboratory tests to assess the calcium-phosphate metabolism were performed in all patients. The results of densitometry were interpreted in 37 IBD patients. Results: LI was diagnosed in 23.2% patients with CD, 22.6% with UC, and 21.2% children with AP-FGID, (p = 0.9). Moreover, 9.5% patients with CD, in 21.4% with UC, and in 51.5% with AP-FGID had optimal concentration of 25(OH)D (p = 0.0002). Hypocalcemia was diagnosed in 21% of patients with CD, 16.1% with UC patients, AP-FGID patients had normal calcium levels (p = 0.02). There was no difference in concentrations of total calcium, phosphorus, and 25(OH)D between patients on low-lactose diet and normal diet (p > 0.05). BMD Z-score ≤ −1 SD was obtained by 12 CD patients (48%), and 6 with UC (50%). Conclusion: The use of a low-lactose diet in the course of lactose intolerance in children with inflammatory bowel diseases has no effect on the incidence of calcium-phosphate disorders and reduced bone mineral density.