The mathematical analysis for plasma disappearance curve of aflatoxicosed animals, subsequently injected with 45Ca was determined. The analysis showed that the three main compartments of the calcium pool (plasma, bone and the labile calcium pool on the surface of bone and soft tissues) had been affected. Specifically, the fractional rate constant for migration of 45Ca from plasma pool to the labile pool had been diminished to its third value. This led to a corresponding reduction in the calcium content of the bone ash. The probable mechanism by which aflatoxin B1 affects calcium dynamics may be interpreted by the inhibitory effect of aflatoxin in the hydroxylation mechanism of vitamin D3 into an active intermediate. During aflatoxicosis (induction of 15 days) the animals entered a state of calcium deficiency, secondary to intestinal absorption inhibition. This was followed by bone resorption and disturbance of the fractional removal rate constant among different calcium compartments.