Is there a difference between zinc oxide tablets and zinc gluconate?

Yes,but neither best: Zinc can be difficult to absorb. Zinc oxide is poorly absorbed and is probably best for topical use (as a sunscreen). Zinc gluconate is better absorbed and is commonly used in lozenges for treating colds. However, research shows that zinc picolinate is much better absorbed than zinc gluconate. Thus, i recommend supplementing with zinc picolinate. See www.Ncbi.Nlm.Nih.Gov/pubmed/3630857.