Adult patients with either type 1 or type 2 diabetes will be enrolled with baseline measurement of visual acuity, contrast sensitivity, color vision, threshold macular perimetry, macular pigment optical density, optical coherence tomography, glycosylated hemoglobin, blood lipids and serum vitamin D status. A multi-component dietary supplement containing ingredients currently available over the counter in the US will be taken for six months and repeat measurements of the above parameters obtained.
