Uses: Since molybdenum's activities in humans are so newly known, it does not have wide usage. Even the uses suggested in some nutritional texts are under question and require more research. Molybdenum may help prevent anemia by helping mobilize iron, provided there are sufficient iron stores. The suggestions that it protects the teeth from dental caries and that it prevents sexual impotence are not yet supported by definitive research. Molybdenum deficiency may reduce uric acid formation; this was not previously thought to be a problem, but it may be important to supplement molybdenum to maintain uric acid levels in midnormal range for the antioxidant function as well as possible others.

There are few research findings to suggest that molybdenum may play a role in preventing cancer and definitely none to suppport its use in cancer treatment. Adding molybdenum to the soil and diet has helped reduce the incidence of esophageal cancer in the Lin Xian area of China's Hunan Province, which had the highest incidence in the world of this deadly disease. It is unlikely, however, that lack of molybdenum in the soil and, thus, in the diet was a direct cause of the cancer; it was probably due to the production of nitrosamines in the soil that could not be metabolized because of a deficiency in the plants' roots activity of the molybdenum enzyme, nitrate reductase. Nitrates and nitrites, such as those in hot dogs, lunch meats, and other cured meats, also increase food levels of nitrates, which can lead to the formation of carcinogenic nitrosamines in the stomach. Both vitamin C, which helps detoxify nitrosamine, and nitrate reductase, which needs molybdenum to function, can help reduce the levels of this carcinogenic chemical as it has done for the Chinese esophageal cancer rates secondary to low soil molybdenum. It is also possible that molybdenum can help protect the body from nitrosamine formation after consumption of foods high in nitrates or nitrites, such as lunch meats.

Deficiency and toxicity: Molybdenum, like most trace minerals, is required in a specific narrow range of daily intake; amounts much greater than this may be toxic. Animals given large amounts experience weight loss, slow growth, anemia, or diarrhea, though these effects may be more the result of low levels of copper, a mineral with which molybdenum competes. In people who are sensitive to it, high doses of molybdenum may lead to high uric acid levels and gouty arthritis symptoms related to increased action of the enzyme xanthine oxidase.

Information about molybdenum deficiency is limited as well. Low soil levels of molybdenum lead to increased soil and plant levels of nitrates and nitrosamines, which increase risk of cancer, especially in the esophagus and stomach. Increased sensitivity to sulfites used in foods may be related to low molybdenum and deficient sulfite oxidase enzymes. In animals, molybdenum-deficient diets seem to produce anorexia, weight loss, and decreased life span. In humans, deficiency may lead to visual problems, rapid heart rate and breathing, and depression of consciousness.

Requirements: As with other newly recognized trace minerals, there is no specific RDA for molybdenum. The amount provided by the average diet ranges widely, from 50-500 mcg. a day. A safe and sensible amount of added molybdenum is from 150-500 mcg. for adults and 50-300 mcg. for children. A molybdenum-rich yeast may be available as an added nutrient, which usually contains a lot of other minerals and B vitamins. Sodium molybdate, which recently has come on the market, can be taken by people who want more molybdenum, though intake should be limited to 500 mcg. daily. It is probably best to take molybdenum in a general multivitamin and to take 2-3 mg. of copper daily as well, because of the potential copper loss with molybdenum supplementation. Further research is required, but it appears that molybdenum is very important for optimum health and longevity.