The role of vitamin D metabolites in the prevention of tibial dyschondroplasia

Dietary supplementation with 1,25-dihydroxyvitamin D, but not vitamin D itself, has been shown to be effective in completely preventing tibial dyschondroplasia (TD) in broilers. This procedure is equally effective whether the incidence of TD is enhanced by feeding predisposing diets imbalanced in Ca/P content or by genetic selection. Cellular studies have suggested that the lesion of TD may be caused by a slowing of the rate of chondrocyte differentiation, leading to the accumulation of transitional chondrocytes. When these accumulations become too large, degeneration may occur leading to the development of the dyschondroplastic lesion. Evidence has been obtained that 1,25-dihydroxyvitamin D may prevent TD by stimulating chondrocyte differentiation and thus inhibiting the initial accumulation of these transitional chondrocytes.