Serum response to supplemental macular carotenoids in subjects with and without age-related macular degeneration

Macular pigment (MP) is composed of lutein (L), zeaxanthin (Z) and meso-zeaxanthin (MZ). The present study reports on serum response to three different MP supplements in normal subjects (n 27) and in subjects with age-related macular degeneration (AMD) (n 27). Subjects were randomly assigned to: Group 1 (20Â mg L and 2Â mg Z), Group 2 (10Â mg L, 2Â mg Z and 10Â mg MZ) or Group 3 (3Â mg L, 2Â mg Z and 17Â mg MZ). Serum carotenoids were quantified at baseline, and at 4 and 8 weeks using HPLC. Response data for normal and AMD subjects were comparable and therefore combined for analysis. We report response as the average of the 4- and 8-week concentrations (saturation plateau). Serum L increased significantly in Group 1 (0·036Â μmol/l per mg (269Â %); P<Â 0·001) and Group 2 (0·079Â μmol/l per mg (340Â %); P<Â 0·001), with no significant change in Group 3 (0·006Â μmol/l per mg (7Â %); P=Â 0·466). Serum Z increased significantly in Group 1 (0·037Â μmol/l per mg (69Â %); P=Â 0·001) and Group 2 (0·015Â μmol/l per mg (75Â %); P<Â 0·001), with no significant change in Group 3 (Â -Â 0·0002Â μmol/l per mg (Â -Â 6Â %); P=Â 0·384). Serum MZ increased significantly in Group 1 (0·0094Â μmol/l (absolute value); P=Â 0·015), Group 2 (0·005Â μmol/l per mg; P<Â 0·001) and Group 3 (0·004Â μmol/l per mg; P<Â 0·001). The formulation containing all three macular carotenoids (Group 2 supplement) was the most efficacious in terms of achieving the highest combined concentration of the three MP constituent carotenoids in serum, thereby potentially optimising the bioavailability of these compounds for capture by the target tissue (retina).