Molybdenum [Nutrition]

Molybdenum, a trace element essential for micro-organisms, plants, and animals, was discovered in 1778 by a Swedish chemist named Karl Scheele. Initially mistaken for lead, molybdenum was named after the Greek work molybdos, meaning lead-like. In the 1930s, it was recognized that ingestion of forage with high amounts of molybdenum by cattle caused a debilitating condition. In the 1950s, the essentiality of molybdenum was established with the discovery of the first molybdenum-containing enzymes. In humans, only 4 enzymes requiring molybdenum have been identified to date: sulfite oxidase, xanthine oxidase, aldehyde oxidase, and mitochondrial amidoxime-reducing component (mARC). Sulfite oxidase, an enzyme found in mitochondria, catalyzes oxidation of sulfite to sulfate, the final step in oxidation of sulfur amino acids (cysteine and methionine). Xanthine oxidase converts hypoxanthine to xanthine, and further converts xanthine to uric acid, preventing hypoxanthine, formed from spontaneous deamination of adenine, from leading to DNA mutations if paired with cytosine in place of thymine. Aldehyde oxidase is abundant in the liver and is an important enzyme in phase 1 drug metabolism. Finally, mARC, discovered less than a decade ago, works in concert with cytochrome b5 type B and NAD(H) cytochrome b5 reductase to reduce a variety of N-hydroxylated substrates, although the physiologic significance is still unclear. In the case of each of the molybdenum enzymes, activity is catalyzed via a tricyclic cofactor composed of a pterin, a dithiolene, and a pyran ring, called molybdenum cofactor (MoCo) (1).

J. A. Novotny, and C. A. Peterson,Molybdenum, Advances in nutrition, 2018, 9, 272-273.

Background: This work represents the first part of a progressive review of AuSPEN's 1999 Guidelines for Provision of Micronutrient Supplementation in Adult Patients receiving Parenteral [intravenous] Nutrition, in recognition of the developments in the literature on this  since that time.

Methods: A systematic literature review was undertaken and recommendations were made based on the available evidence and with consideration to specific elements of the Australian and New Zealand practice environment. The strength of evidence underpinning each recommendation was assessed. External reviewers provided feedback on the guidelines using the AGREE II tool.

Results: Reduced doses of manganese, copper, chromium and molybdenum, and an increased dose of selenium are recommended when compared with the 1999 guidelines. Currently the composition of available multi-trace element formulations is recognised as an obstacle to aligning these guidelines with practice. A paucity of available literature and limitations with currently available methods of monitoring trace element status are acknowledged. The currently unknown clinical impact of changes to trace element contamination of parenteral solutions with contemporary practices highlights need for research and clinical vigilance in this area of nutrition support practice.

Conclusions: Trace elements are essential and should be provided daily to patients receiving parenteral nutrition. Monitoring is generally only required in longer term parenteral nutrition, however should be determined on an individual basis. Industry is encouraged to modify existing multi-trace element solutions available in Australia and New Zealand to reflect changes in the literature outlined in these guidelines. Areas requiring research are highlighted

Osland, E. J., Ali, A., Isenring, E., Ball, P., Davis, M., and Gillanders, L., Australasian Society for Parenteral and Enteral Nutrition guidelines for supplementation of trace elements during parenteral nutrition, Asia Pacific Journal of Clinical Nutrition, 2014, 23, 545-554.

A very thorough study of Mo uptake and recommended levels is available.

Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc, Panel on Micronutrients, Subcommittees on Upper Reference Levels of Nutrients and of Interpretation and Use of Dietary Reference Intakes, and the Standing Committee on the Scientific Evaluation of Dietary Reference Intakes, Food and Nutrition Board, National Academy Press, 2001 Chapter 11 Molybdenum.

The Recommended Dietary Allowance for adult men and women is 45 microg/day. The average dietary intake of molybdenum by adult men is 109 microg/day and women is 76 microg/day. The Tolerable Upper Intake Level is 2000 microg/day, a level based on impaired reproduction and growth in animals. The main quantitative conclusions are summarised here. The reader should consult the original for definitions, general discussion and methodology.  

Plasma studies were conducted in healthy breast-fed infants and in patients with phenylketonuria at the age of 4 weeks, and the plasma investigations were repeated at the ages of 4 and 12 months. Molybdenum concentrations in formulas exceed those in human milk. Molybdenum intake and retention in all infants with phenylketonuria were more than 18 times those of breast-fed infants.The plasma concentrations reflected these differences. A median of 0.04 mu g/l was assessed in breast-fed infants at 4 weeks and less than 0.02 mu g/l at 4 months of age. Comparative results of infants with phenylketonuria were 2.9 mu g/l and 2.5 mu g/l, respectively. There were no significant differences between the groups at 12 months of age. The phenylketonuria diets investigated showed excessive retention and plasma concentrations of the essential trace element molybdenum in early infancy. In view of these findings, the present practice of molybdenum fortification should be revised

Sievers, E., Arpe, T., Schleyerbach, U., and Schaub, J., Molybdenum supplementation in phenylketonuria diets: Adequate in early infancy?, Journal of Paediatric Gastroenterology and Nutrition, 2000, 31, 57-62.

An isotope dilution method was developed to determine molybdenum in 0.5 mL blood plasma by ICP-MS. The effect of dietary intake on plasma molybdenum was determined for twelve young men (ages 22–33 y). This is an important paper which includes a discussion of the instrumentation and experimental procedures, including the avoidance of contamination, required to determine accurately molybdenum at the low levels found in plasma. It is suggested that earlier values for molybdenum in whole blood may be as much as ten times too high. Some typical results are these.

For subjects consuming a very low Mo diet (22 microg/day) plasma molybdenum decreased from 8.2 ± 0.5 to 6.1 ± 0.5 nmol/L after 13 days of low molybdenum intake and was 5.1 ± 0.5 nmol/L after 24 days.

Another group consumed the low molybdenum diet for 102 days followed by high molybdenum (467 microkg/day for 18 days and the plasma molybdenum rose to 16.5 ± 0.6 nmol/L during the high molybdenum period.

The results demonstrate that, in contrast to most other essential minerals, plasma molybdenum reflects low and high dietary molybdenum intakes within 14 days and may a useful indicator of low and high dietary intakes.

Turnlund, J.R. and Keyes, W. R., Plasma molybdenum reflects dietary molybdenum intake, Journal of Nutritional Biochemistry, 2004, 15, 90-95.

The intestinal absorption of molybdenum in healthy human volunteers has been measured by simultaneous oral and intravenous administration of the stable isotopes ⁹⁵Mo and ⁹⁶Mo, and the results were analysed using the convolution integral technique. The results showed that molybdenum ingested in liquid form was rapidly and totally absorbed into the circulation under ordinary intake regimes. The rates and extent of absorption were lower for composite meals, and also for increasing levels of administration. This information can be helpful in the application of the new ICRP model of the human alimentary tract.

Giussani, A., Arogunjo, A. M., Cantone, M. C., Tavola, F., and Veronese, I., Rates of intestinal absorption of molybdenum in humans, Applied Radiation and Isotopes, 2006, 64, 639-644.

The intestinal uptake, systemic kinetics and urinary excretion of molybdenum in 17 healthy human volunteers has been studied using stable isotopes of molybdenum measuring their concentrations by activation analysis and mass spectrometry in blood plasma (⁹⁶Mo) following intravenous injection and urine (⁹⁵Mo) following oral administration. Molybdenum was administered in water (up to 5 mg Mo in 100 ml), and 0.5 ? 1 mg Mo in black tea (100 ml) mg and in vegetables (cress and green salad) and solid food (baby formula, tomatoes, bean soup). The object of the experiments was to develop a compartmental model for the systemic kinetics of molybdenum. The main observations were

Molybdenum was eliminated very rapidly from the circulation. Urinary excretion of molybdenum was intense and rapid in the few hours after incorporation. After 24 h excretion rates were negligible.

Intestinal absorption of the oral tracer Mo into the systemic circulation depended on the form in which it was administered reflecting its bioavailability

in water solution 100% absorption for administration up to 1 mg,

with solid foods reduced to 50% absorption

with black tea 10% or less absorption.

Only the process of renal excretion is influenced by the total amount of molybdenum in the systemic circulation.

The amount eliminated via the renal pathway was observed to be dependent on several factors: form and modality of administration and the total amount of circulating molybdenum.

Modelling urinary excretion of molybdenum after oral and intravenous administration of stable tracers. Giussani A, Cantone MC, Höllriegl V, Oeh U, Tavola F, Veronese I. Radiat Prot Dosimetry. 2007 Jun 19; [Epub ahead of print]

An expanded compartmental model of molybdenum kinetics to determine rates of molybdenum distribution during molybdenum depletion and repletion was developed. The model was based on a clinical study in which 4 men consumed a low-molybdenum diet of 22 mu g/d (0.23 mu mol/d) for 102 d, followed by a high molybdenum diet of 467 mu g/d (4.9 mu mol/d) for 18 d. Stable isotopes ¹⁰⁰Mo and ⁹⁷Mo were administered orally and intravenously, respectively, at several time points during the study, and serial samples of plasma, urine, and feces were analyzed for ¹⁰⁰Mo and ⁹⁷Mo , and total Mo. Based on plasma, urine, and fecal molybdenum levels, kinetic parameters of distribution and elimination were determined. The rates of molybdenum distribution and elimination were different during depletion and repletion. During high intake, urinary molybdenum excretion was greater than during low intake. Fractional tissue storage of molybdenum was lower during high intake than during low intake. Low intake results in an adaptation to conserve body Mo, and that high intake results in an adaptation to eliminate Mo. The model also suggested that food-bound molybdenum was approximately 16% less bioavailable than purified Mo. The model suggested that an intake of 43 mu g/d (0.45 mu mol/d) would be sufficient to maintain plasma molybdenum levels at steady state. This is a minimum estimate because subjects in this study were in a molybdenum-sparing state. These findings provide an understanding of the adaptations in molybdenum metabolism that take place during depletion and repletion

Novotny, J. A. and Turnlund, J. R., Molybdenum kinetics in men differ during molybdenum depletion and repletion, Journal of Nutrition, 2006, 136, 953-957.

The objectives of this study were to determine physiologic adaptations that occur when humans are exposed to a wide range of molybdenum intake levels and to identify the pathways that are influenced by dietary intake. Four males consumed each of 5 daily molybdenum intakes of 22, 72, 121, 467, and 1490 microg/d (0.23,0.75, 1.3, 4.9, and 15.5 micromol/d) for 24 d each. During each treatment period, oral and intravenous doses of (100)Mo and (97)Mo were administered. Serial plasma, urine, and fecal samples were analyzed for labeled and unlabeled molybdenum. Compartmental modeling was used to determine rates of distribution and elimination at each dietary intake level. Three pathways were sensitive to daily molybdenum intake. With increasing intake, absorption and urinary molybdenum excretion increased, whereas the fraction deposited in tissues decreased. Kinetic analysis suggested a daily intake of 115-120 microg/d (1.20-1.25 micromol/d) would maintain initial plasma molybdenum levels at their prestudy values and that their prestudy dietary intake was well above the Recommended Dietary Allowance of 45 microg/d. The physiological adaptations to changing intake that the model demonstrated may help prevent molybdenum deficiency and toxicity.

Molybdenum intake influences molybdenum kinetics in men. Novotny JA, Turnlund JR. J Trace Elem Med Biol. 2007;21(1):8-16. Epub 2007.

The supplementation of formulas for premature infants with Mo should be rescinded until there is evidence for its necessity

Plasma was collected at 3, 16, and 52 wk and

72 h balances were performed at 3 wk of age.

For premature infants

n = 18,

gestational age less than or equal to 32 wk,

birth weight less than or equal to 1500 g

Increased Mo intake and low relative urinary excretion resulted in a retention of 4.4 (0.99-7.77) mug Mo/kg initially in premature infants (median, range). Parallel plasma concentrations were 5.5 (2.5- 7.3) mug Mo/L,, declining to 2.36 (0.73-3.87) mug Mo/L at 4 wk.

For healthy formula-fed term infants

n = 14

Initial plasma 1.49 (0.29-1.7) mug Mo/L (p < 0.05), with no significant differences later.

Sievers, E., Schleyerbach, U., Arpe, T., Garbe-Schonberg, D., and Schaub, J., Molybdenum supply of very low-birth-weight premature infants during the first months of life, Biological Trace Element Research, 2001, 80, 97-106.

Mo balances were assessed for formula Mo concentrations from 0.125 to 2.704 mu mol/l.

For infants with a "low" Mo intake 0.024 (0.020-0.035) mu mol/ kg per day

urinary excretion was 0.02 (0.008-0.045) mu mol/kg per day

retention 0.0006 (-0.03 to 0.008) mu mol/kg per day.

For infants with a "high" intake 0.284 (0.2270.487) mu mol/kg per day,

urinary excretion was 0.243 (0.118-0.378)

retention of 0.022 (-71.1 to 141.44) mu mol/kg per day.

Since the median urinary excretion exceeded 60% of the Mo intake at low and high intakes, sufficient resorption but minimal retention was assessed at low intakes of Mo. In view of the limited knowledge of long-term exposure to an elevated molybdenum intake and the substantial retention observed at higher intakes, upper limits should be set for molybdenum concentrations in preterm infant formulas

Sievers, E., Oldigs, H. D., Dorner, K., Kollmann, M., and Scbaub, J., Molybdenum balance studies in premature male infants, European Journal of Pediatrics, 2001, 160, 109-113.

Recommended dietary allowances of molybdenum

A very thorough study of Mo uptake and recommended levels is available here. The Recommended Dietary Allowance for adult men and women is 45 microg/day. The average dietary intake of molybdenum by adult men is 109 microg/day and women is 76 microg/day. The Tolerable Upper Intake Level is 2000 microg/day, a level based on impaired reproduction and growth in animals. The main quantitative conclusions are summarised here. The reader should consult the original for definitions, general discussion and methodology.

Recommended daily allowances 0.15 – 0.5 mg/d
Min daily requirement Mo 2 microg Mo/kg body weight
WHO

A recommended daily allowance of molybdenum for an adult has been established at 0.2 mg [Dulce, 1968]. In addition daily molybdenum intakes from drinking water and ambient air are almost neglible and should be considered only in molybdenum mining areas. A rapid rate of molybdenum excretion has been observed after the administration of high doses and it has been suggested that this observation is likely to represent one of the defence and regulatory mechanisms of the organism [Lener, 1978].

Dulce, H. J., D. Zahnaerztl. Z., 1968, 23, 101.
Lener, J., Molybden jako faktor zivotního prostredíz hlediska jeho nekterých úcinku. Doktorská disertacní práce, Praha, 1978.

Four young men were fed a low-molybdenum diet (22 microg/d) for 102 d followed by 18 d of the same diet supplemented to contain 467 microg/d. The study was to determine the minimum dietary molybdenum requirement of healthy young men. Stable isotopes of molybdenum were used as tracers. The study demonstrated that subjects could not consistently attain balance with the low-molybdenum diet, but balance improved with time, and no signs of molybdenum deficiency were observed. Molybdenum was very efficiently absorbed at both intakes of dietary molybdenum and urinary excretion increased as dietary molybdenum increased. Molybdenum turnover was significantly slower when dietary molybdenum was low. The minimum dietary molybdenum requirement is approximate 25 microg/d less than the current recommended amount of 75 microg/d [Turnlund et al., 1995.]

Turnlund, J.R., Keyes, W.R., Peiffer, G.L., Chiang, G., Molybdenum Absorption, Excretion, And Retention Studied With Stable Isotopes In Young Men During Depletion And Repletion, American Journal Of Clinical Nutrition, 1995, 61,1102-1109.

A set of reference values has been established for chromium, copper, iodine, iron, manganese, molybdenum, and zinc to replace Recommended Dietary Allowances (RDAs), Estimated Safe and Adequate Daily Dietary Intakes published in 1989. AU RDAs, Adequate Intakes (AIs), and Tolerable Upper Intake Levels (ULs] reported are summarized, commented and compared with the DACH reference values 2000. For some elements including molybdenum, ULs have been established.

Low-birth-weight infants might be at risk for Mo deficiency because they are born before adequate stores for Mo can be acquired, they have rapid growthrequiring increased intakes, and they frequently receivesupplemental parenteral nutrition and total parenteralnutrition unsupplemented with molybdenum. Conclusions: The authors speculate that an intravenous intake of 1 mu g/kg/d (10nmol/kg/d) and an oral intake of 4-6 mu g/kg/d (40-60nmol/kg/d) would be adequate for the LBW infant.

Friel, J.K., MacDonald, A.C., Mercer, C.N., Belkhode, S.L., Downton, G., Kwa, P.G., Aziz, K., Andrews, W.L., Molybdenum requirements in low-birth-weight infants receivingparenteral and enteral nutrition, Journal Of Parenteral And Enteral Nutrition, 1999, 23, 3, 155-159.

The molybdenum levels found in human urine samples determined spectrophotometrically were between 0.5-2.1 mu g/100 ml.

Amin, A.S., Determination of molybdenum in human urine by spectrophotometric method using thiazolylazo compounds as chromogenic reagents Analytical Letters, 1999, 32, 1575-1587.

Molybdenum in urine (summary) [Barceloux, 1999] US residents (National Health and Nutrition Examination Survey [NHANES III) a 95th percentile concentration of 168 microg Mol/L. The maximum concentration was 688 microg Mo/L.

Danish population: concentration in urine was 42.5 microg/L with an 95% reference interval of 10-124 microg/L.

Barceloux, D.G., Molybdenum, Journal Of Toxicology-Clinical Toxicology, 1999, 37, 231-237

Mean molybdenum creatinine levels in urine in 128 Danish inhabitants by ICP-MS were 42.5 mu g /l, (3.89 mu g Mo /mmol creatinine) using Mo-95 and 41.5 1 mu g/ l(3.81 mu g Mo /mmol creatinine) using Mo-98 [Sabbioni, 1998]. The precision was 8.6% and the recovery of added NIST 1643c certified reference material was 94%. The limit of detection was 0.2 mu g/ l. The difference between men and women reached the level of significance only after the values were corrected for the creatinine concentration, There was no influence of age on the Mo concentration Specific effects of different food and beverage intakes could not be demonstrated, with the exception of a positive correlation between butter consumption and Mo concentration.

Sabbioni, E., Iversen, B.S., Menne, C., White, M.A., Kristiansen, J., Christensen, J.M.,Inductively coupled plasma mass spectrometric determination of molybdenum in urine from a Danish population, Analyst, 1998, 123, 81-85.

The technique of electrothermal atomic absorption spectrometry has been developed and standardised for the determination of Mo and other metals in human urine. [Campillo et al., 1999].

Values for Mo from 4 subjects were

Metals concentrations were determined in 110 urinary calculi samples from hospital patients in Jordan using X-ray fluorescence (XRF) and atomic absorption spectroscopy (AAS). Twenty-one calculi were pure calcium oxalate (CaOax), 29 were mixed calcium oxalate/uric acid, 23 were mixed calcium oxalate/phosphate (apatite), 25 were phosphate calculi (apatite/struvite), five were mixed calcium oxalate monohydrate/struvite, four were urate calculi (mixed ammonium acid urate/sodium acid urate) and three were pure cystine calculi. Mean metal concentrations were: Ca 48.18, Na 1.56, K 0.9, Mg 3.08, Fe 1.17, Al 0.49, Zn 0.7, Cu 0.19, Mn 0.029, P 10.35, S 1.88, Sr 0.306, Mo 0.2, Cr 0.146, Co 0.05, Ni 0.014 %.

It is noteworthy that the concentration of molybdenum in the urate and cystine calculi (0.65, 0.58 wt-%) is ten-fold greater than the concentration in the other calculi, a selectivity effect not found for the other metals and reflecting possibly the involvement of molybdenum in urate production via the molybdoenzyme xanthine oxidase.

Abboud, I. A., Concentration effect of trace metals in Jordanian patients of urinary calculi, Environmental Geochemistry and Health, 2008, 30, 11-20.

Determined by Inductively Coupled Plasma-Mass Spectrometry. Molybdenum limit of detection was 0.003 mg/kg fresh weight. Molybdenum concentrations (mg/kg fresh weight) in most foodstuffs were below 0.2. Exceptions with higher levels were offal (1.2), canned vegetables (0.31), nuts (0.96). The dietary exposure to Mo estimated from typical diets was in mg/day for the total population 0.11, for adult consumers 0.12 mean and 0.21 upper range.

Ysart, G., Miller, P., Crews, H., Robb, P., Baxter, M., DeLArgy, C., Lofthouse, S., Sargent, C., Harrison, N.,Dietary exposure estimates of 30 elements from the UK TotalDiet Study, Food Additives And Contaminants,1999, 16, 9,391-403.

The total concentrations of Na, Mg, P, K, Ca, Mn, Fe, Co, Ni, Cu, Zn, Se and Mo in soybean flour and in extract of soybeanflour were determined by ICP - AES and ICP - MS. The soybean flour extract wassubmitted to fractionation by size exclusion chromatography ona Fractogel EMD Bio SEC (S) column with 0.2 mol/L Tris-HNO3buffer pH 7.5. Molybdenum was mostly found in a low- molecular fraction (2-3 kDa).

Fingerova, H., Koplik, R., Study of minerals and trace element species in soybean flour, Fresenius Journal Of Analytical Chemistry, 1999, 363, 5- 6, 545-549.

The average values for molybdenum content in white wines are within the range1.77x10-7-1.83 x 10-7 mol l-1.

Bejan, D., Kinetic-catalytic-spectrophotometric determination of low concentrations of molybdenum in white wines, Analytica Chimica Acta, 1999, 390, 1-3, 255-259.

The preparation of the recently released Standard Reference Material (SRM) 2383 Baby Food Composite and the process used for value assignment of nutrient concentrations are reported. SRM 2383 can be used as a control material when assigning values to in-house control materials and when validating analytical methods for measuring proximates, vitamins, and minerals in baby food and similar matrixes. The SRM was prepared as a commercial baby food would be prepared, with the same ingredients. Molybdenum determined by ICP MS was 0.065 mg/kg.

Sharpless, K.E., Gill, L.M., Margolis, S.A., Wise, S.A., Elkins, E., Preparation of Standard Reference Material 2383 (Baby Food Composite) and use of an interlaboratory comparison exercise for value assignment of its nutrient concentrations, Journal Of Aoac International, 1999, 82, 2, 276-287.

Market baskets containing sixty food items included in the average Swedish diet were purchased from three shops in four major Swedish cities during autumn 1987. Food items were selected on the basis of food-balance-sheet data. Freeze-dried homogenates representative of each city were analysed for twelve essential or toxic mineral elements. The energy content of the market baskets (11.5 MJ) corresponded to the reference value for male adults. The molybdenum content was 150 mug, within the safe and adequate intake values given in the US recommended dietary allowance (Food and Nutrition Board, National Research Council, 1989).

Becker, W. And Kumpulainen, J., Contents Of Essential And Toxic Mineral Elements In Swedish Market-Basket Diets In 1987, British Journal of Nutrition, 1991, 66, 151-160.

Dietary intake of minerals and trace elements in rice on the Jamaican market

Twenty-five rice brands, available on the Jamaican market, and a local field trial sample were collected and analyzed for 36 essential, non-essential and toxic elements using four techniques: flame atomic absorption spectrophotometry (F-MS), inductively coupled plasma optical emission spectrometry (ICP-OES), instrumental neutron activation analysis (INAA), and total reflection X-ray fluorescence (TXRF). The mean values for both white and brown rice respectively for calcium (127 mg/kg; 104 mg/kg), chromium (0.08 mg/kg; 0.157 mg/kg), copper (1.65 mg/kg; 2.96 mg/kg), iron (22.3 mg/kg; 20.1 mg/kg), magnesium (371 mg/kg; 1205 mg/kg), manganese (10.5 mg/kg; 26.5 mg/kg), molybdenum (0.790 mg/kg; 0.770 mg/kg), phosphorus (1203 mg/kg; 3361 mg/kg), potassium (913 mg/kg; 2157 mg/kg). selenium (0.108 mg/kg; 0.131 mg/kg), sodium (6.00 mg/kg; 15.1 mg/kg), sulfur (1131 mg/kg; 1291 mg/kg) and zinc (15.6 mg/kg; 20.2 mg/kg) were used to calculate intake values. The percentage contribution to Provisional Tolerable Weekly Intakes were also estimated for the toxic elements aluminum (6.6-17.9%), arsenic (7.8-10.2%), cadmium (5.1-9.0%) and mercury (3.2-12.0%) with ranges dependent on white or brown rice consumption and gender. It was concluded that, for most essential elements, rice does not significantly contribute to mineral nutrition. The local field trial sample yielded encouraging results in terms of uptake of toxic elements. (C) 2012 Elsevier Inc. All rights reserved

Antoine, Johann M. R., Fung, Leslie A. H., Grant, Charles N., Dennis, Haile T., and Lalor, Gerald C., Dietary intake of minerals and trace elements in rice on the Jamaican market, Journal of Food Composition and Analysis, 2012, 26, 111-121.

Iron and molybdenum in a dietetic pharmaceutical preparation (multivitamin-multimineral preparation, Alcala Farma S.L., Spain) have been determined by flame atomic absorption spectrometry (FAAS) after dry ashing at 600 degreesC. The interest of the paper is the precision of Mo determination.

Concentration in the preparation ca 0.08 mgMo/g.

Linearity of response was verified for concentrations 1.00 to 6.00 mg/ l of molybdenum.

Precision of the methods, performed under conditions of repeatability and reproducibility, gave relative standard deviations of 1.0 and 6.5%, respectively.

Mean recoveries determined after spiking dietetic preparation placebos 95.2 to 102.9%

The limit of detection 129 mug/l.

Quantification limits were 433 mug/l

Day-to-day and analyst-to-analyst variability was 4.5% for molybdenum.

Results show the suitability of the method for measurement of iron and molybdenum in a complex matrix sample such as a dietetic pharmaceutical preparation.

Canfranc, E., Abarca, A., Sierra, I., and Marina, M. L., Determination of iron and molybdenum in a dietetic preparation by flame AAS after dry ashing, Journal of Pharmaceutical and Biomedical Analysis, 2001, 25, 103-108.

Dietary intakes of 25 pairs of Japanese children and their parents of 12 toxic and essential trace elements using 7-day duplicate diet composites were determined. Intake of molybdenum (children 103, adults 131 mg/day were close to the recommended values.

Aung, N. N., Yoshinaga, J., and Takahashi, J. I., Dietary intake of toxic and essential trace elements by the children and parents living in Tokyo Metropolitan Area, Japan, Food Additives and Contaminants, 2006, 23, 883-894.

Mo release from joint replacements

No significant differences were observed in mean serum and urinary levels of Mn, Mo and Ni between patients who had undergone arthroplasty [joint replacement, e.g. knee, hip] and control subjects.

Iavicoli, I., Gianluca, F., Alessandrelli, M., Rafaella, C., De Santis, V., Salvatori, S., Alimonti, A., and Carelli, G., The release of metals from metal-on-metal surface arthroplasty of the hip, Journal of Trace Elements in Medicine and Biology, 2006, 20, 25-31.

The concentrations of 14 trace elements in blood plasma are reported for 158 patients in 3 dialysis surgeries having chronic kidney failure. Molybdenum concentrations/microg l-1 were:

Normal group: minimum 0.27 median 0.66 maximum 1.7

Reference: lower limit 0.3 upper limit 1.2

Dialysis patients: 0.6 3.2 7.7

Keller, T., Gehring, L., Loser, T., Trace element disorders in patients with chronic kidney failure during dialysis, Nieren-Und Hochdruckkrankheiten, 1998, 27,12,522-532.

The role of blood and blood components in the process of molybdenum metabolism is not as yet clear. Molybdenum concentrations in blood and blood serum have been determined under both normal and pathological conditions. The serum molybdenum concentration in blood donors was 1.8 ng/g, in hospital personnel 3.4 ng/g and in patients with degenerative diseases 1.2 ng/g. Patients treated for specific processes were found to have 7.2 ± 0.3 ng/g of molybdenum in their whole blood [Butt et al.,1964]. The fate of 99Mo in human subjects has also been studied [Rosoff and Spencer, 1964]. A single tracer dose of 50-100 microCi was injected intravenously. After injection blood levels of the isotope fell rapidly (from 5% to 0-5% within 1 to 8 h). The extent to which molybdenum accumulates in persons exposed to low daily concentrations of molybdenum is not known but if the animal experiments are taken as a guide it is likely that the rate of accumulation of molybdenum is small.

Butt, E. M., Nusbaum, R. E., Gilmour, T. C. and Didio, S. L., Arch. Environ. Health, 1964, 8, 52.
Rosoff, B. and Spencer, H., Nature, 1964, 202, 410.

Skin lesions from a metal implant containing molybdenum ― alleged histiocytosis associated with molybdenum

A unique case of intralymphatic histiocytosis with granuloma formation associated with orthopaedic metal implants is reported. Asymptomatic reddish-brown nodules were observed on the left knee of a seventy-five year old man; an orthopaedic metal implant had been inserted in the knee for a knee joint disorder. Histopathological examination revealed typical features of mixed cell granuloma with many dilated lymphatics that contained many histiocytes from the upper dermis to subcutaneous fat tissue. Biopsy specimens were analysed qualitatively by energy-dispersive X-ray spectroscopy and were positive for molybdenum, one of the constituents of the metal implant. It is suggested that the synovial fluid containing molybdenum had drained into the skin lesion from the synovial cavity of the left knee. The lesions disappeared following drainage.

[Intralymphatic: situated within or introduced into a lymphatic vessel

Histiocytosis: an abnormal increase in the number of certain immune cells, called histiocyte cells.

Histiocyte: A macrophage (cell which ingests particulate materials) found within the tissues.

Granuloma: a localised accumulation of macrophages around the site of some continuing stimulus, e.g. injury, inflammation or infection, having their cell membranes fused together so as to form multinucleated giant cells.]

COMMENT. The case of intralymphatic histiocytosis associated with an orthopaedic metal implant reported in this paper is unique. Any significance to be attached to molybdenum in the biopsy specimens is not clear and is not discussed. There is, of course, no control.

Watanabe, T., Yamada, N., Yoshida, Y., and Yamamoto, O., Intralymphatic histiocytosis with granuloma formation associated with orthopaedic metal implants, British Journal of Dermatology, 2008, 158, 402-404.