This study will evaluate the effects of a novel multi-component dietary supplement on the visual function and retinal structure of patients with diabetes with both no diabetic retinopathy and mild to moderate diabetic retinopathy. This is a placebo-controlled trial and neither subjects nor examiners will know if any given subject is taking active supplement or placebo.

The hypothesis is that the supplement will improve visual function and retinal structure in subjects on active supplement

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.

Inclusion Criteria:

• diabetes mellitus diagnosed at least 5 years
• age greater than or equal to 18 years
• English speaker

Exclusion Criteria:

• proliferative diabetic retinopathy or severe non-proliferative retinopathy
• clinically significant macular edema
• corrected visual acuity less than 20/30 in either eye
• diagnosis of other serious eye disease (glaucoma, age-related maculopathy)
• less than 18 years old
• non-English speaker
• no known allergy or sensitivity to any supplement ingredients