retinol-binding protein: Gut integrity and circulating immunoglobulins

Vitamin A (retinol) is required to maintain immunity and epithelial turnover and is a key micronutrient needed for combating infection. Vitamin A actions on the immune system are diverse and cannot be accounted for by a single effect or mechanism. The actions of retinol in maintaining gut integrity in humans and immunoglobulin levels in mice was investigated. For 30 children, performance on the lactulose/mannitol test, a test commonly used to assess intestinal barrier function, was inversely correlated ( ) with serum retinol concentra-P p.012 tions. Thus, children with lower serum retinol, and presumably poorer vitamin A nutritional status, are more likely to have impaired intestinal integrity. Knockout mice that have im-pairments in plasma retinol transport have circulating immunoglobulin levels that are half those observed in matched wild type mice. No differences were observed in B and T cell populations present in spleen, thymus, and bone marrow. Vitamin A (retinol) is acquired from the diet and is needed for maintaining the general health of higher animals and hu-mans [1]. It is required for normal vision, for maintaining nor-mal growth and differentiation, for an uncompromised immun