Herpes zoster (HZ) results from a reactivation of latent varicella-zoster virus (VZV). HZ and its most common complication, termed postherpetic neuralgia (PHN), often cause long-term psychological distress and physical disabilities leading to profoundly negative impacts on the quality of patients' lives. The incidence and severity of HZ and PHN increase with advanced age as a consequence of declining cell-mediated immunity. Aging has been linked to progressive senescence of the immune system and also is associated with a greater susceptibility to nutritional deficiencies. Suppressing VZV reactivation depends on intact cell-mediated immunity, which requires adequate nutrients to maintain its efficient function. Contrarily, nutritional deficiencies may lead to dysfunction of the host immune responses. Recently, micronutrient deficiencies have been shown to increase the risk of HZ and PHN and to affect the immune response to vaccinations, whereas nutritional supplements effectively reduce herpetic pain and pain in patients with PHN. As the elderly population grows, the incidence and severity of HZ and PHN are expected to increase and cause a substantial financial burden on the health care system. Thus, enhancing knowledge of the risk factors of HZ and PHN and developing better interventions to treat and prevent HZ and PHN are important to public health. This article provides an overview of the present understanding of the association among nutritional deficiencies, diminished cell-mediated immunity, and the risk of HZ and PHN, and then illustrates the potential of nutritional intervention in the prevention, vaccination, and management of HZ and PHN.