Table 1.

Randomised controlled trials (RCTs) of the effect of omega-3 supplementation that included blood sampling at baseline and post-intervention.

Reference	Blood Sample Type	Equation and Pearson’s Correlation [39]	Omega-3 Index Equivalence at Baseline	Omega-3 Index Equivalence Post-Intervention	Outcomes
Svensson et al. 2006 [24]	Serum phospholipid fatty acids	Y = 0.93x + 0.55 R = 0.94	6.1%	9.8%	Myocardial infarction 3.9% versus 12.6% (p = 0.036) Major coronary events 6.8% versus 16.5% (p = 0.043) Note the large increase in omega-3 fatty acid status (38%) achieved Omega-3 fatty acid status is in the cardio-protective zone.
Einvik et al. 2010 [29]	Serum fatty acids	Y = 0.94x + 1.17 R = 0.74	6.8%	10.6%	All-cause mortality 5% versus 8.5% (p = 0.063) Note the large increase in omega-3 fatty acid status (36%) achieved Omega-3 fatty acid status is in the cardio-protective zone.
Kromhout et al. 2010 [27]	Plasma cholesteryl esters fatty acids	Y = 1.59x + 2.05 R = 0.85	7.0%	8.4%	No significant outcomes. Note the small increase in omega-3 fatty acid status (17%) achieved.
Galan et al. 2010 [30]	Plasma fatty acids	Y = 0.94x + 1.17 R = 0.74	4.7%	6.0%	No significant outcomes. Note the small increase in omega-3 fatty acid status (22%) achieved. Omega-3 fatty acid status of 6% is not in the cardio-protective zone
Wu et al. 2013 [33]	Serum phospholipid fatty acids	Y = 0.93x + 0.55 R = 0.94	4.7%	6.2%	No significant outcomes. Note the small increase in omega-3 fatty acid status (24%) achieved. Omega-3 fatty acid status of 6% is not in the cardio-protective zone