Molybdenum intake influences molybdenum kinetics in men

Area of Science:

• Human physiology
• Trace element metabolism

Background:

• Molybdenum is an essential trace element crucial for various enzymatic functions.
• Understanding molybdenum homeostasis is vital for preventing both deficiency and toxicity.

Purpose of the Study:

• To investigate physiological adaptations to a wide range of molybdenum intake levels in humans.
• To identify metabolic pathways influenced by dietary molybdenum.

Main Methods:

• Four males participated in a controlled study with five different daily molybdenum intake levels (22 to 1490 microg/d).
• Stable and radioactive isotopes of molybdenum ((100)Mo and (97)Mo) were administered orally and intravenously.
• Plasma, urine, and fecal samples were analyzed to track molybdenum distribution and elimination.
• Compartmental modeling was employed to quantify kinetic parameters at each intake level.

Main Results:

• Three key pathways showed sensitivity to molybdenum intake: absorption, urinary excretion, and tissue deposition.
• Increased molybdenum intake led to higher absorption and urinary excretion.
• A greater fraction of molybdenum was deposited in tissues at lower intake levels.

Conclusions:

• A daily molybdenum intake of 115-120 microg/d appears sufficient to maintain baseline plasma molybdenum levels.
• The study participants' usual intake likely exceeded the Recommended Dietary Allowance (45 microg/d).
• The identified physiological adaptations may play a role in preventing molybdenum imbalance.