Manganese Provision in Parenteral Nutrition: An Update

Area of Science:

• Clinical Nutrition
• Trace Element Metabolism

Background:

• Manganese (Mn) is an essential micronutrient crucial for metalloenzyme activity.
• It is a component of parenteral nutrition (PN), though requirements are low.
• Assessing Mn status is challenging, with whole blood concentration measurement having limitations like contamination artifacts.

Purpose of the Study:

• To review the role of manganese in parenteral nutrition.
• To discuss the risks and presentation of manganese toxicity in PN patients.
• To evaluate current recommendations and product formulations for manganese supplementation.

Main Methods:

• Literature review on manganese metabolism, toxicity, and supplementation in PN.
• Analysis of current PN trace element product compositions.
• Discussion of diagnostic methods for manganese status and toxicity.

Main Results:

• Manganese toxicity is a recognized complication of PN, particularly with cholestasis or high doses, presenting with parkinsonian symptoms or hypermanganesemia.
• Whole blood manganese measurement can be unreliable due to contamination.
• Current multi-trace element products often exceed recommended manganese doses (55 μg/d).

Conclusions:

• Caution is advised for manganese supplementation in long-term PN (>1 month).
• Withholding manganese is recommended if hypermanganesemia or cholestasis occurs.
• Newer PN products with appropriate manganese doses are expected to decrease toxicity incidence.