Why Zinc and Immunity Are Linked

The link between zinc and immunity is famous but the mechanism is often fuzzy. Thymulin makes it concrete: this thymic peptide is biologically active only when bound to zinc. No zinc, no activity — which is exactly why zinc deficiency impairs T-cell function and immunity.

Thymulin drives T-cell differentiation in the thymus, and as the thymus involutes with age, its output falls. That decline is one driver of immunosenescence — the gradual weakening of immunity in older adults. Members discuss thymulin as the biochemical bridge connecting nutrition, the thymus, and age-related immune decline.