This Article Full Text Full Text (PDF) Services Download to citation manager PubMed PubMed Citation

Effect of Zinc Supplementation on the Immune Status of Healthy Older Individuals Aged 55–70 Years: The ZENITH Study

¹ Northern Ireland Centre for Food and Health (NICHE), University of Ulster, Coleraine, Northern Ireland.
² Department of Haematology, Belfast City Hospital, Northern Ireland.
³ Centre de Recherche en Nutrition Humaine d'Auvergne, Unité Maladies Métaboliques et Micro-nutriments INRA, Centre de Recherche de Clermont-Ferrand, Saint Genès Champanelle, France.

Address correspondence to Julie M. W. Wallace, PhD, Northern Ireland Centre for Food and Health (NICHE), University of Ulster, Coleraine, Northern Ireland BT52 1SA. E-mail: j.wallace{at}ulster.ac.uk

Aging is associated with alterations in the immune system, effects which may be exacerbated by inadequate zinc (Zn) status. We examined the relationship between Zn status and markers of immunity and the effect of supplementation with 15 mg or 30 mg Zn/d for 6 months on immune status in healthy individuals. Zn status was assessed by dietary intake and biochemical indices. Immune status was assessed by multiple flow cytometric methods. At baseline, Zn concentration was positively associated with lymphocyte subpopulation counts and T-lymphocyte activation. Zn supplementation of 30 mg/d significantly lowered B-lymphocyte count, albeit at month 3 only. Lower doses of Zn (15 mg Zn/d) significantly increased the ratio of CD4 to CD8 T lymphocytes at month 6. Overall, these findings suggest that total Zn intake (diet plus supplementation) of up to 40 mg Zn/d do not have significant long-term effects on immune status in apparently healthy persons aged 55–70 years.