Two different animal studies measured retinal activity in this way. The ALC supplementation normalized abnormal electroretinograms. Both forms of L-carnitine discussed here appear to be safe, although extensive formal toxicology tests have not been completed. Safety for young children, pregnant or nursing women, or those with severe liver or kidney disease has not been established. Magnesium As covered in Diabetes and Nutritional Deficiencies , people with diabetes are prone to magnesium deficiency.
Some researchers theorize that magnesium deficiency contributes to retinopathy in diabetes.
However, we have no direct evidence that magnesium supplements can help prevent this condition. A reasonable dosage of magnesium is in the range of 200 to 400 mg daily. If diarrhea occurs, the dosage should be reduced. People with kidney disease should avoid doses higher than 100 to 200 mg daily. At this dosage, magnesium is believed to be safe.