**2.3.2 Biomarkers: Fatty acids, vitamin D and E**

The distribution of fatty acids in the plasma phospholipid fraction as well as Vit D and Vit E will be analyzed in plasma samples from the same aliquots at a commercial laboratory in Oslo (AS Vitas; http://www.vitas.no/) using solid phase extraction and gas chromatography.

## **2.4 Measurement of exposure to virus (viral infections)**
