The Role of Micronutrient Deficiency in Delayed Immunosenescence and Healthy Ageing

Abstract

Immunosenescence presents a major clinical challenge by increasing susceptibility to infections, reducing vaccine efficacy, and elevating the risk of chronic diseases. This state is characterized by a paradoxical combination of immunodeficiency and chronic low-grade inflammation termed "inflammaging." Key hallmarks include thymic involution, a shrinking T-cell repertoire, accumulation of senescent cells, and dysregulated inflammatory responses. This review explores the compelling evidence that micronutrient deficiencies, which are highly prevalent in the elderly, are not merely a consequence but an active accelerator of this immune decline. The mechanisms linking deficiency to immunosenescence are detailed, including increased oxidative stress and DNA damage, impaired lymphocyte proliferation, and dysregulated cytokine production. Preclinical and clinical studies demonstrate that repleting deficient levels of key nutrients like vitamin D and zinc can rejuvenate thymic function, improve T-cell responses, and enhance vaccine efficacy in older adults. The review concludes that targeted nutritional interventions, particularly synergistic multi-nutrient approaches, represent a viable strategy to bolster immune resilience in the ageing population, thereby promoting healthier longevity and reducing the burden of age-related immune pathology.