Fatty acid composition of erythrocyte samples was determined from blood collected at the first visit for each subject in both studies. Whole blood was collected in EDTA tubes on ice and centrifuged (4°C, 1700 × g, 10 minutes). Erythrocyte fatty acid methyl esters were prepared using boron trifluoride in methanol[15 (link), 16 (link)]. Fatty acid methyl esters were analyzed by gas chromatography (Shimadzu, Columbia, MD) using a 30-m Omegawax 320 (Supelco-Sigma) capillary column. Conditions of gas chromatography include: helium flow rate was 30 ml/min, oven temperature started at 175°C held for 4 min then increased to 220°C at a rate of 3°C/min. Retention times were compared to authentic standards for fatty acid methyl esters (Supelco-Sigma, St. Louis, MO and Matreya, Inc., Pleasant Gap, PA) and fatty acids are reported as percent of total identified. The intra-assay coefficients of variation were 3.8% for OA, 4.2% for LA, 13.5% for EPA, 4.8% for DPA and 6.5% for DHA. The sum of the three long chain Ω3 fatty acids = EPA+DPA+DHA, e.g., LC-Ω3-SUM. Fatty acid composition of erythrocytes is shown in Table 2.