Effects and interactions of vitamins A, D(3), and E in broiler chickens

Experiments were conducted to investigate the effects and interactions of vitamins A, D{dollar}sb3{dollar} and E in broiler chickens. High levels of vitamins A and E were supplemented to basal diets containing zero, marginal, and adequate dietary vitamin D{dollar}sb3.{dollar} Chicks were exposed to direct fluorescent light to determine if the effect of high dietary levels of vitamins A and E on the utilization of vitamin D{dollar}sb3{dollar} was prior to, during or after absorption. The effect of low and high dietary levels of vitamin A on the utilization and amelioration of toxicity of dietary vitamin D{dollar}sb3,{dollar} 25-(OH)D{dollar}sb3{dollar} and 1,25-(OH){dollar}rmsb2Dsb3{dollar} were also evaluated by adding increasing levels of these compounds to the basal diet.; High dietary levels of vitamins A and E decreased body weight, bone ash, and increased the incidence of vitamin D-type rickets. However, these effects of vitamins A and E were produced only when marginal dietary levels of vitamin D{dollar}sb3{dollar} were added to the diet. The addition of adequate vitamin D{dollar}sb3{dollar} totally prevented the effects of high dietary vitamins A and E. Significant (p {dollar}le{dollar} 0.05) vitamin A x D{dollar}sb3{dollar} and vitamin E x D{dollar}sb3{dollar} interactions were observed for bone ash, and incidence of rickets in most of the experiments.; Both UV light and increasing vitamin D{dollar}sb3{dollar} increased body weight, bone ash, plasma calcium, and decreased the incidence of rickets resulting from the high levels of vitamin A or E in the diet. The addition of dietary vitamin D{dollar}sb3{dollar} to birds exposed to UV light produced a slight positive response for most of the criteria measured suggesting that birds did not have enough exposure to direct fluorescent light, and that UV light alone was not enough to produce maximum response for the parameters measured.; Groups of birds fed high dietary vitamin A required more vitamin D{dollar}sb3,{dollar} 25-(OH)D{dollar}sb3{dollar} or 1,25-(OH){dollar}rmsb2Dsb3{dollar} to achieve maximum body weight, bone ash, plasma calcium and to reduce the incidence of rickets. High dietary vitamin A ameliorated the toxic effects of high levels of vitamin D{dollar}sb3,{dollar} 25-(OH)D{dollar}sb3{dollar} or 1,25-(OH){dollar}rmsb2Dsb3.{dollar} High levels of vitamin D{dollar}sb3,{dollar} 25-(OH)D{dollar}sb3,{dollar} or 1,25-(OH){dollar}rmsb2Dsb3{dollar} reduced the concentration of vitamin A in plasma and liver suggesting an interaction between these vitamins prior to or during the absorption process at the intestinal level.