Inflammation and biomarkers of micronutrient status

Investigations to discover new biomarkers of nutrition highlighted the fact that inflammation and infection were cross-cutting issues complicating interpretation of status. Collaborative groups of nutritionists, immunologists, clinicians and statisticians were set up to investigate the issues, and some are now reporting their findings.

Recent work on the vitamins A, D, E and C and the elements iron, zinc and selenium are reported in this review. In clinical settings, experts emphasize the unreliability of nutritional biomarkers to reflect status, but some advocate the use of albumin to assist interpretation. In apparently healthy people with subclinical inflammation, one method to correct data on vitamin A and iron stores using C-reactive protein and alpha-1-acid glycoprotein is available, and two studies report on its use; others methods are currently being investigated.

Biomarkers of most micronutrients are the plasma concentrations of the respective vitamins or minerals and, irrespective of nutritional status, many are reduced by inflammation; the main exception is ferritin which is increased. Different methods are being investigated to better interpret nutritional data in the presence of infection or inflammation, and nutritionists who work with apparently healthy people need to be aware of subclinical inflammation to avoid exaggerating or underreporting nutritional results.