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Administration's Total Diet Study ranging from 76 to 109 µg/day for adult females and males, respectively. Human milk contains very low levels of molybdenum, and after the first month of lactation, furnishes only approximately 1.5 µg/day (Casey and Neville, 1987). little is known about the chemical form or nutritional bioavailability of molybdenum in foods. Most public water supplies would be expected to contribute between 2 to 8 µg of molybdenum per day (NRC, 1980), which would constitute 10% or less of the lower limit of the provisional recommended intake. Since most diets should meet the molybdenum requirements of humans, supplements of additional molybdenum are not recommended.

Estimated Safe and Adequate Daily Dietary Intakes

Aside from the exceptions discussed above, no disturbances in uric acid or sulfate production have ever been related to molybdenum deficiency in humans. The human requirement apparently is so low that it is easily furnished by common U.S. diets. Therefore, the provisional recommended range for the dietary intake of molybdenum, based on average reported intakes, is set at 75 to 250 µg/day for adults and older children. The range for other age groups is derived through extrapolation on the basis of body weight.

Excessive Intakes and Toxicity

The toxicity of molybdenum presents a substantial problem for animal nutrition because molybdenum is antagonistic to the essential element copper (Mills and Davis, 1987). Adverse effects of high environmental concentrations of molybdenum were observed in humans living in a province of the USSR (Koval'skiy and Yarovaya, 1966). The authors suggested that the excessive dietary intake of 10 to 15 mg/day may be the cause of a high incidence of a goutlike syndrome associated with elevated blood levels of molybdenum, uric acid, and xanthine oxidase. Even a moderate dietary exposure of 0.54 mg/day has been associated with loss of copper in the urine (Deosthale and Gopalan, 1974).

References

Abumrad, N.N., A.J. Schieider, D. Steel, and L.S. Rogers. 1981. Amino acid intolerance during prolonged total parenteral nutrition reversed by molybdate theraps. Am. J. Clin. Nutr. 34:2551-2559.