Linking vitamin a and childhood immunizations

Although studies conducted over the last twenty-five years have demonstrated that vitamin A and related retinoids are immune enhancers, the use of vitamin A and related retinoids to enhance responses to immunization has been limited. Numerous animal studies have now demonstrated that vitamin A and related retinoids, when given at or prior to immunization, will enhance antibody responses and cell-mediated immune responses to protein antigens. Recent studies with humans show that vitamin A supplementation enhances the IgG response to tetanus toxoid, and that related retinoids can be used to enhance antibody responses to protein antigens. Vitamin A enhances immune responses to poor immunogens, and this may be relevant to vaccines which are characterized by low se-roconversion rates. Although most known adjuvants have too many side effects for human use, vitamin A and related retinoids appear to enhance antibody and cell-mediated immunity without severe side effects. Vitamin A, through its metabolite...