Hello, Welcome to Just Answer and thanks for your question. Anything that contains wheat, rye or barley is off-limits for someone with celiac disease. Avoiding these is the most important thing. Any additive in vitamin capsules would be far, far down the list of things to avoid, since they are in such minuscule quantities. On packaged foods you can read the labels for there three grains and for the word "gluten." The list below contains some of the things to look for.