Aim: To assess the vitamin A status of patients with Crohn's disease (CD) by evaluating serum retinol levels and the relative dose response (RDR) test (liver retinol stores).
Methods: Vitamin A nutritional status was measured by serum retinol obtained by high performance liquid chromatography and the RDR test for evaluation of the hepatic stores. Body composition was performed by densitometry by dual-energy X-ray absorptiometry. Vitamin A dietary intake was assessed from a semi-quantitative food frequency questionnaire.
Results: This study included 38 CD patients and 33 controls. Low serum retinol concentrations were detected in 29% of CD patients vs 15% in controls (P < 0.005). The RDR test was positive in 37% of CD patients vs 12% in controls, which indicated inadequate hepatic vitamin A stores (P < 0.005). Individuals with hypovitaminosis A had lower BMI and body fat compared with those without this deficiency. There was no association between vitamin A deficiency and its dietary intake, ileal location, presence of disease activity and prior bowel resections.
Conclusion: Patients with CD have higher prevalence of vitamin A deficiency, as assessed by two independent methods.
Keywords: Body composition; Crohn’s disease; Relative dose response test; Serum retinol; Vitamin A.