Blood Manganese Unit Converter
Blood Manganese Unit Converter
Convert whole blood manganese between µg/L, ng/mL, nmol/L and µmol/L. Manganese is the one metal here that is also an essential nutrient, which is why the test is ordered as often for parenteral nutrition as for an occupational exposure.
Blood Manganese converter
Mass ⇄ molarWhole blood manganese 18.3 µg/L, the upper limit Mayo prints
The conversion, and the specimen it depends on
µg/L = nmol/L × 0.054938
µmol/L = µg/L × 0.0182023
- 18.2023
- from manganese’s atomic weight, 54.938043. Manganese is effectively monoisotopic, which is why CIAAW quotes it to eight figures with an uncertainty in the last
- whole blood
- the correct specimen. ARUP states that "less than 5 percent of manganese present in circulation resides in the serum", and publishes a serum interval of 0.0–2.0 µg/L against a whole blood 4.2–16.5
- trace element-free tube
- royal blue EDTA or sodium heparin. ARUP rejects specimens in other tubes outright, and recommends a repeat in a certified tube whenever a result is raised
Worked example
Whole blood manganese 18.3 µg/L, the upper limit Mayo prints
18.3 × 18.2023 = 333.1 nmol/L
= 18.3 ng/mL = 0.3331 µmol/L
At Mayo's limit; above ARUP's 16.5 µg/L; and well above the 260 nmol/L (14.28 µg/L) upper limit the SAS laboratory publishes
Whole blood and serum manganese are not the same test
| Source | Specimen | Interval | As printed |
|---|---|---|---|
| Mayo MNB | Whole blood | 4.7 – 18.3 µg/L | 4.7-18.3 ng/mL |
| ARUP 0099272 | Whole blood | 4.2 – 16.5 µg/L | 4.2-16.5 µg/L |
| SAS | Whole blood | 4.40 – 14.28 µg/L | 80 – 260 nmol/L |
| ARUP 0099265 | Serum | 0.0 – 2.0 µg/L | 0.0- 2.0 ug/L |
| SAS | Serum or plasma | 0.60 – 2.31 µg/L | 11 – 42 nmol/L |
| SAS | Neonates, 3 – 4 days | 17.5 – 63.6 µg/L | 318 – 1157 nmol/L |
What raises whole blood manganese
| Cause | Mechanism |
|---|---|
| Contamination at collection | The commonest explanation for an isolated high result |
| Parenteral nutrition | Supplemented manganese with no biliary route to excrete it |
| Cholestasis and cirrhosis | Manganese is excreted in bile; obstruct that and it accumulates |
| Occupational exposure | Welding fume, mining, iron and steel production, ferroalloys |
| Iron deficiency | Shared intestinal transport raises manganese absorption |
Why the specimen decides the answer
Whole blood manganese in µg/L becomes nmol/L on multiplication by 18.2023, from manganese’s atomic weight of 54.938043. ng/mL and µg/L are identical, so Mayo’s 4.7–18.3 ng/mL and ARUP’s 4.2–16.5 µg/L are directly comparable — and they do not quite agree, with upper limits 11% apart. The UK Supraregional Assay Service publishes 80–260 nmol/L, whose upper limit is 14.28 µg/L on this mass, so the three reference laboratories span 14.3 to 18.3 µg/L at the top.
A much larger difference is the specimen. ARUP states flatly that "less than 5 percent of manganese present in circulation resides in the serum", and its serum interval of 0.0–2.0 µg/L is roughly an eighth of its whole blood interval. Manganese partitions into the red cells, so serum and whole blood are two different measurements rather than the same one at a different scale. A serum result read against a whole blood interval looks like severe deficiency, and the reverse looks like intoxication. Mayo supplies whole blood only, with the instruction to send the original tube and not to aliquot.
Contamination is the other dominant error, and it is the first thing to consider when a result comes back high. ARUP’s interpretive note is explicit: elevated results "may be suspected to be due to contamination" and should be confirmed on a second specimen in a certified trace element-free tube. Both laboratories require royal blue tubes and ARUP rejects anything else.
When the result is real, the differential is short. Manganese is excreted almost entirely in bile, so cholestasis and cirrhosis raise it without any external source at all, and parenteral nutrition does the same from the other end — supplemented manganese with no working route out. Occupational exposure is welding fume, mining and ferroalloy work. Chronic excess produces manganism, an extrapyramidal syndrome that mimics Parkinson disease and responds poorly to levodopa, and a characteristic T1 hyperintensity in the basal ganglia on MRI. For the other essential trace metals read on the same panel, see serum copper and serum zinc.
Frequently asked questions
How do I convert blood manganese from µg/L to nmol/L?
Multiply by 18.2023, from manganese’s atomic weight of 54.938043. A whole blood manganese of 18.3 µg/L is 333.1 nmol/L. To go back, multiply nmol/L by 0.054938.
Why is whole blood the right specimen for manganese?
Because manganese partitions into the red cells. ARUP states that under 5% of circulating manganese is in the serum, and its serum interval, 0.0–2.0 µg/L, is about an eighth of its whole blood interval of 4.2–16.5 µg/L. The two are not interchangeable.
What is the most likely cause of a single raised manganese?
Contamination at collection. ARUP recommends confirming any elevated result on a second specimen drawn into a certified trace element-free tube before pursuing it, and both laboratories require a royal blue tube.
Why does liver disease raise blood manganese?
Manganese is excreted almost entirely in bile, so cholestasis or cirrhosis removes the main route out and it accumulates. The same mechanism makes patients on long-term parenteral nutrition with manganese supplementation vulnerable.
Is there such a thing as manganese deficiency?
Not as a recognised clinical syndrome in people eating a normal diet. Manganese is abundant in grains, nuts, beans and tea, and an isolated low whole blood result in an otherwise well patient is of doubtful significance.
Related calculators
References
- Mayo Clinic Laboratories. Manganese, blood (MNB). Test catalogue, test ID 89120; 2026. 4.7–18.3 ng/mL, all ages; "Send whole blood specimen in original tube. Do not aliquot".
- ARUP Laboratories. Manganese, whole blood. Laboratory Test Directory 0099272; 2026. "4.2-16.5 µg/L"; "Elevated results may be suspected to be due to contamination, confirmation with a second specimen collected in a certified trace element-free tube is recommended".
- ARUP Laboratories. Manganese, serum. Laboratory Test Directory 0099265; 2026. "0.0- 2.0 ug/L"; "Less than 5 percent of manganese present in circulation resides in the serum".
- Supraregional Assay Service, Trace Element laboratory. Manganese. sas-centre.org; accessed October 2026. Whole blood 80–260 nmol/L, serum or plasma 11–42 nmol/L, neonates at 3–4 days 318–1157 nmol/L.
- Agency for Toxic Substances and Disease Registry. Toxicological Profile for Manganese. Atlanta, GA: US Department of Health and Human Services.
- Commission on Isotopic Abundances and Atomic Weights, IUPAC. Standard Atomic Weights 2024. ciaaw.org; accessed October 2026. As 74.921595(6), Mn 54.938043(2), Al 26.9815384(3), Cr 51.9961(6), Co 58.933194(3), Tl [204.382, 204.385]; for the interval elements the IUPAC abridged values Tl 204.38, C 12.011, N 14.007 are used.
Not medical advice. For healthcare professionals and education. Reference intervals vary by laboratory and assay — always use your own laboratory's. Never base a dose or a treatment decision on this page alone. Full disclaimer at calcengines.com/disclaimer/