NUTRITION THERAPY TO TREAT ZINC DEFICIENCY IN CELIAC DISEASE

Abstract

Background: Nutritional deficiencies are frequent in celiac disease (CeD), and one of the most common is zinc (Zn) deficiency. Supplements are often prescribed to treat Zn deficiency; however, they have been associated with adverse events and reduced absorption of other minerals. Data collected in our clinic showed that 38% of CeD patients would opt for a diet to improve Zn, however, such a diet may be challenging due to food interactions with phytic acid, which blocks Zn absorption. Therefore, the feasibility and efficacy of a Zn-optimized diet compared to supplementation is unknown. Aims: To assess the feasibility of the protocol and collect data on estimated effect sizes for secondary outcomes to plan a properly powered randomized controlled trial (RCT). Methods: We conducted an open-label, pilot RCT. CeD patients were randomized to Zn supplementation (Zn gluconate 25mg) or a Zn-optimized diet for 3 months and followed up with a 3-month pragmatic approach. We evaluated enrollment rates and adherence to both interventions. Plasma and urine Zn, stool samples, and questionnaires were collected pre- and post-intervention. Results: We enrolled 28 participants and 16 of them have completed the study. Interim analysis shows an enrollment fraction of 26% (i.e. 28/108 eligible participants), and a dropout rate of 17.9%. Eighty-two % of participants allocated to the Zn-supplement intervention and 50% in the dietary intervention were compliant at 3 months. Based on the effect size for normalization of plasma Zn at 3 months, 142 participants are required for an adequately powered RCT in the future. There were no significant differences in gastrointestinal or extra-intestinal symptoms, quality of life, anxiety and depression or adverse events between interventions. Conclusion: Based on this preliminary analysis, recruitment of participants will take 6 months longer than expected. Assessment of reasons for diet non-adherence will allow implementation of strategies to improve feasibility.