Submitted to: Journal of Nutritional Biochemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 1, 2004
Publication Date: February 1, 2004
Citation: Turnlund, J.R., Keyes, W.R. 2004. Plasma molybdenum reflects dietary molybdenum intake. Journal of Nutritional Biochemistry. 15:90-95. Interpretive Summary: A wide range of plasma molybdenum concentrations have been reported, but the relationship between dietary molybdenum and plasma concentrations has not been studied in humans. Therefore, we undertook a study in young men to evaluate the effect of dietary molybdenum on plasma molybdenum. Twelve young men consumed a very low molybdenum diet for 24 days. After 14 days, their plasma molybdenum concentrations fell significantly. When higher levels of molybdenum were consumed, plasma molybdenum concentrations increased significantly. The changes were observed within 14 days. The results demonstrate that plasma molybdenum is a good indicator of dietary molybdenum and may be useful in evaluating intake. In contrast, plasma concentrations of most minerals do not reflect intake, except when intake is extremely low or high.
Technical Abstract: The relationship between plasma molybdenum (Mo) and dietary intake has not been investigated in humans. We developed an isotope dilution method to determine molybdenum in 0.5 mL blood plasma by ICP-MS and conducted a study to determine the effect of dietary intake on plasma molybdenum. Twelve young men consumed a very low Mo diet (22 g/d) for 24 d while confined to the WHNRC metabolic research unit and plasma molybdenum was monitored. 97Mo was infused in four of the subjects (Group 1) to follow its clearance from the blood. The other eight remained in unit for 120 d (an additional 96 d). Four consumed the 22 g/d molybdenum diet for 102 d followed by 467 g/d for 18 d (Group 2) and four consumed five levels of dietary molybdenum for 24 d each (Group 3). 100Mo was added to the diet one or more times at each dietary level. Total plasma molybdenum and 100Mo were monitored throughout the study. Plasma molybdenum in the 12 subjects decreased from 8.2 +/-0.5 to 6.1 +/- 0.5 nmol/L after 13 d of low molybdenum intake and was 5.1 +/- 0.5 nmol/L after 24 d. In Group 2, average plasma molybdenum was 7.8 +/- 0.9 nmol/L at the beginning of the study, 5.4 +/- 0.4 nmol/L during the 102 d low molybdenum period, and 16.5 +/- 0.6 nmol/l during the high molybdenum period. Plasma molybdenum in Group 3 was 4.2 +/- 2.1 nmol/L at 22 g/d; 5.8 +/- 2.5 nmol/L at 72 g/d; 6.6 +/- 2.3 nmol/L at 121 g/d; 19.7 nmol/L +/- 2.1 at 467 g/d; and 43.9 +/- 2.1 nmol/L at 1490 g/d. The results demonstrate that, in contrast to most other essential minerals, plasma molybdenum reflects low and high dietary molybdenum intakes within 14 d and may a useful indicator of low and high dietary intakes.