Drs Thong and Robertson comment

AT10 (vitamin D2); in which AT10 was considered as equivalent to vitamin D2. AT10 (dihydrotachysterol) is quite different from vitamin D2 which is ergocalciferol. Although both compounds, after their hydroxylation in the liver and kidney would be effective on serum calcium levels, they differ in that AT1O may be rachitogenic in long usage but vitamin D is the compound recommended for