Zinc Deficiency Treatment in Celiac Disease: Supplementation Versus Diet

A Pilot Study to Evaluate the Feasibility of a Zinc-optimized Gluten-free Diet Compared With Supplements to Treat Zinc Deficiency in Celiac Disease

Micronutrient deficiencies are common amongst celiac disease (CeD) patients due to consumption of a restrictive and nutritionally unbalanced gluten-free diet (GFD) in addition to slow intestinal villi healing. Preliminary data of 221 patients attending our Celiac Disease Clinic at McMaster University show that 64% of patients on a GFD have nutrient deficiencies with zinc (Zn) deficiency affecting 48% of treated CeD patients. Dietary supplements are prescribed to treat Zn deficiency and it is unclear whether Zn levels can be restored with optimizing Zn in diet. This project will evaluate the the feasibility of dietary therapy to treat Zn deficiency in CeD in comparison to supplementation. Additional objectives of this pilot study, are to assess the efficacy of Zn optimized GFD compared to Zn supplements in 1) normalizing plasma Zn levels and 2) improving CeD gastrointestinal and extra-intestinal symptoms at 3 and 6 month. Subjects will be recruited from McMaster Celiac clinic. This randomized controlled trial aims to recruit 50 CeD participants with two treatment groups; zinc optimized diet (guided by dietitian to achieve target of 11 mg/day for females and 14 mg /day for males) or zinc oral supplementation (25 mg zinc gluconate tablet/day; 7 mg elemental Zn) with a total study a total study period of 6 months and 4 visits. To be included in the study the investigators require celiac diagnosed patients confirmed through CeD serology and duodenal biopsies adhering to a GFD > 6 months and plasma Zn ≤9.3 µmol/L. Questionnaires will be used to assess presentation of symptoms, dietary adherence, quality of life, depression and anxiety. The trial would be considered to be feasible if the enrolment fraction (i.e., number of enrolled patients /number of eligible patients) is 60% or above.

Inclusion Criteria:

• Diagnosis of CeD based on specific CeD serology (elevated anti-tissue transglutaminase IgA, deaminated gliadin peptides-Immunoglobulin G or anti-endomysial antibodies IgA) and confirmed by duodenal biopsies showing villous atrophy (Marsh 3a or greater);
• Adopting a gluten-free diet for at least 6 months;
• Untreated Zn deficiency (Zn plasma levels ≤9.3 µmol/L)

Exclusion Criteria:

• Are already on a Zn optimized diet;
• Treatment with Zn supplements or multivitamins containing >11 mg of Zn in the last month;
• Prior allergic reaction to Zn supplements;
• Treatment with antibiotics or probiotics supplements in the last 30 days;
• Pregnancy or lactation
• Current infection in the last 30 days;
• Intestinal obstruction, short gut (remnant bowel <180 cm), or any serious illness considered by the investigator that will interfere with the study procedure or results. Data including medication and supplementation will be recorded in case report form and Zn content added to total Zn in the analysis.
• Untreated pancreatic insufficiency (fecal elastase <200).