Ham is a holiday tradition in many homes. Hams, like turkey may be injected with a solution during processing that contains gluten. According to the following manufacturers, listed products are gluten-free. Always read labels carefully because not all products by these manufacturers are gluten-free.
How to Cook Ham by Peggy Trowbridge Filippone, About.com Guide to Home Cooking
How to Heat Fully Cooked Ham by Linda Larsen, About.com Guide to Busy Cooks