The biological properties of molybdenum are also very important. It is not only an essential trace element for plants but also for animals. Molybdenum is one of the main components of molybdenin protease in Azotobacter; it is also one of the main components of plant nitrate reductase; it can also activate phosphatase activity, promote the synthesis and transportation of sugar and starch in crops; it is conducive to the early maturity of crops. Molybdenum is one of the seven important micronutrients. Molybdenum is also one of the basic components of xanthine oxidase and aldehyde oxidase in the liver and intestine of animals, and it is also the basic component of heparin sulfite oxidase. The results show that molybdenum also has the effect of preventing caries. Molybdenum has a strong inhibitory effect on the formation of urinary calculi. A healthy person with a weight of 70kg has 9mg molybdenum in his body. For human beings, molybdenum is one of the second and third transition elements known to be essential to human beings. Compared with the same transition elements, molybdenum has very low toxicity, even can be considered as basically non-toxic. Of course, excessive ingestion will also accelerate the oxidation of the elastic material, acetal phospholipid, in the arterial wall of the human body. Therefore, the incidence of cancer is lower in the areas with high molybdenum content, but the incidence of gout and systemic arteriosclerosis is higher. However, the animals fed with excessive molybdenum forage, especially the long horned animals, are prone to stomach disease.
Metabolic absorption
Molybdenum compounds in diet and drinking water are easily absorbed. About 88% - 93% of the oral intake of soluble ammonium molybdate can be absorbed.  Various sulfur compounds in the diet have a strong inhibition effect on the absorption of molybdenum,
Molybdenum sulfide can only absorb about 5% after oral administration. Molybdate still binds to macroglobulin in blood in the form of molybdate, and has loose binding with red blood cells. Most of the molybdenum in the blood is absorbed by the liver and kidney.
Some of the molybdate radicals in the liver are converted into molybdate enzymes, and the rest are combined with pterin to form molybdate containing cofactors and stored in the liver. The body excretes molybdenum mainly in the form of molybdate through the kidney. When the intake of dietary molybdenum increases, the excretion of molybdenum by the kidney also increases. Therefore, the body keeps the balance of molybdenum through the excretion of kidney rather than the control of absorption. In addition, a certain amount of molybdenum is excreted with bile.