Vitamin A Deficiency and Immunity.

The effect of dietary vitamin A on the immunocompetence of Atlantic salmon (Salmo salar L.)

“…The lack of an effect on the phagocyte respiratory burst may account for the lack of a significant effect of vitamin A intake on phagocyte bactericidal activity in the present study, since the respiratory burst is the principal mechanism by which macrophages kill the strain of A. salmonicida used (Sharp and Secombes 1993). However, this result is in contrast to the reduced respiratory burst activity seen in vitamin A deficient chickens (West et al 1991), and the reduced leucocyte bactericidal activity seen in mammals fed low levels of vitamin A (reviewed by Dhur et al 1991). Vitamin A deficiency did result in a significant reduction in the ability of salmon leucocytes to migrate in vitro.…”

“…The relationship between dietary vitamin A intake and specific humoral responses is also complex, and often apparently contradictory in other animal groups. In humans, for example, there is little effect of vitamin A status on production of specific antibody (reviewed by Dhur et al 1991), yet in vitamin A deficient chickens suppressed primary and secondary responses to T-dependent antigens have been observed, suggesting a lesion in T-cell function (West et al 1991). However, studies of the proliferative response of adult rats have shown B-cell but not T-cell mitogen responses to be reduced by vitamin A deficiency (Van Bennekum et al 1991).…”

Effects of dietary beta-carotene on the immune response of rainbow trout Oncorhynchus mykiss

“…Neither vitamin A nor astaxanthin had any effect on complement activity. 11,30 Even in homeotherms including humans 31,32 data available so far do not show a conclusive relation between dietary bcarotene levels and complement activity. However, alternative serum complement activity has been shown to be more important in fish than in mammals, the levels in fish being several times higher in carp, 58.…”

Effect of dietary vitamin A deficiency on growth performance, feed utilization and immune responses of juvenile Jian carp (Cyprinus carpio var. Jian)

“…In fish, hypovitaminosis A is characterized by poor growth, poor vision, keratinization of epithelial tissue, xerophthalmia, night blindness, haemorrhage in the anterior chamber of the eye and at the base of the fins, and abnormal bone formation (Halver 2002). Vitamin A supplement has a number of significant effects on innate and specific immune responses in homoeotherms (Dhur, Galan & Hercberg 1991; West, Rombout, Van der Zijpp & Sijtsma 1991), consisting of enhancing antibody responses (Jurin & Tannock 1972) and lysozyme activity (West et al . 1991).…”

“…Vitamin A functions in several critical biological processes, including di¡erentiation of epithelial tissue, resistance to infections, proper growth, reproduction and vision (Olson 1994). In ¢sh, hypovitaminosis A is characterized by poor growth, poor vision, keratinization of epithelial tissue, xerophthalmia, night blindness, haemorrhage in the anterior chamber of the eye and at the base of the ¢ns, and abnormal bone formation (Halver 2002).Vitamin A supplement has a number of signi¢cant e¡ects on innate and speci¢c immune responses in homoeotherms (Dhur, Galan & Hercberg 1991;West, Rombout, Van der Zijpp & Sijtsma 1991), consisting of enhancing antibody responses (Jurin & Tannock 1972) and lysozyme activity (West et al 1991). However, there is a paucity of information concerning the relationship between vitamin A and ¢sh immune responses (Evans, Graves, Blazer, Dawe & Graztek 1984;Thompson, Fletcher, Houlihan & Secombes 1994), and some studies have been con¢ned to only several ¢sh species, such as Atlantic salmon (Salmo salar Linnaeus) (Thompson et al1994) and gilthead seabream (Sparus aurata Linnaeus) (Cuesta, Esteban & Meseguer 2002).…”