Details on molybdenum bioavailability in milk?

Question

There have been reports of molybdenum in milk since before 1951. However, supposedly "there [is] no data on bioavailability in cow's milk" after all these years. Most sources I find claim milk contains somewhere on the order of 50 μg/L. I'm having troubles finding more detail. Mostly I'm curious about my daily intake, and possible cheap but still mostly healthy meal replacements for lazy days.

How much molybdenum can I expect (as a low ball estimate) to count towards the daily RDA of 45 μg from the about 35 μg in three cups of milk?

Update:

Perhaps the best way to answer this is to find out in what compounds the molybdenum are in in milk and see if there's any details on those compounds' bio-availability. I know they said the nutrient fed to the cows to increase the molybdenum content was ammonium molybdate, which, along with sodium molybdate and potassium molybdate, should be bioavailable (along with most soluble molybdenum sources). The Soylent discussion site (which is oddly appropriate to why I'm asking), has other citings on their bio-availability listings which confirm this. If I find an answer, I'll post it.

Answer 1

In Dietary Reference Intakes by Institute of Medicine (US) Panel on Micronutrients we can read that RDA for adult men and women is 45 μg/day. The average dietary intake of molybdenum by adult men and women is 109 and 76 μg/day, respectively.

Biego and his coworkers¹ in 1998 reported an average molybdenum concentration of 4 μg/L in human milk with stage of lactation not reported and much higher concentrations of molybdenum in cow's milk (50 μg/L, as does soymilk) and infant formula, however as you suggested - the data on the bioavailability of molybdenum in cow milk and infant formulas are not available.

How much it's per cup of milk - it can really vary on milk, however Diet.com suggest it's around 4.9μg.

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References:

• 1: Biego GH, Joyeux M, Hartemann P and Debry G, 1998. Determination of mineral contents in different kinds of milk and estimation of dietary intake in infants. Food Additives and Contaminants, 15, 775-781.

Answer 2

Diet.com suggests that molybdenum sources in food are between 57% and 88% efficient in absorption rates nutritionally, and additionally lists milk content as 4.9 μg per cup, which is much lower than the suggestions elsewhere. This may be a good lower bound for calculation. However, remember that the tolerable upper limit for adults is considered to be 0.6 mg of molybdenum, according to the European Food Safety Authority as of 2000. Alternatively, Diet.com listed it as 2 mg.