Vitamin A excess

Vitamin A is a fat-soluble vitamin related to bone growth, epithelial tissue metabolism and regeneration, and storage of rhodopsin in the retina. Vitamin A can interfere with the metabolism of chondrocytes and affect the synthesis of chondroitin sulfate. It can also increase the subperiosteal bone and fibrosis the medullary cavity adjacent to bone cancellous. Large doses of vitamin A can increase bone osteoclasts in mice, increase bone resorption, and be prone to fractures; it can also make dog growth plates heal prematurely.