Although the biological effects of manganese deficiency are well established in several animal species, no role in human nutrition has yet been described. Animals rendered manganese deficient show retardation of growth, skeletal & muscular abnormalities, and neurological signs. The human requirement for manganese is very low and, even during prolonged TPN, no clear evidence of deficiency has emerged. However, because of the potential importance of manganese, additives containing the element have been included in TPN regimens. Earlier, some trace element additives contained too much manganese leading to brain abnormalities shown on magnetic resonance imaging and, in a few cases, Parkinson’s Disease-like symptoms. Current additives contain less manganese but children with liver problems can still accumulate this element.

We recommend whole blood samples for assessment of manganese status and long-term occupational exposure. For whole blood where the normal concentrations are about ten-fold higher than in serum, the manganese from contamination is proportionally less significant and so no special precautions are necessary in sampling.

Whole blood concentrations of manganese are significantly raised during pregnancy and show an average three-fold increase in the neonate.

Manganese toxicity is a known problem in metal refining and manganese ore production. Respiratory illness and eventually neurological effects are seen after years of heavy exposure. No guidelines for biological monitoring are available.

Sample Requirements and Reference Ranges for Manganese

* This is the absolute minimum volume; these volumes are insufficient to carry out a repeat analysis in the event of an analytical problem.