Alpha lipoic acid is an important nutrient for mitochondrial function. It has antioxidant properties and can act as a reducer of oxidized forms of vitamins C and E. A number of placebo-controlled clinical trials have found that supplementing with 600 to 1,200 mg of alpha-lipoic acid per day can improve the symptoms of diabetic nerve damage (neuropathy).^5,6,7,8 Animal studies and early clinical research suggest alpha-lipoic acid may also help prevent diabetes-related damage to the small blood vessels and nerves in the eyes (diabetic retinopathy).^9,10

People with type 1 diabetes often have low magnesium levels, and low magnesium status is correlated with poor glucose control and increased risk of complications. In magnesium-deficient pregnant women with type 1 diabetes, the lack of magnesium may even account for the high rate of miscarriages and birth defects associated with type 1 diabetes. Some studies have found that magnesium replenishment using supplements can improve blood glucose control and may reduce the risks of certain diabetes complications, such as cardiovascular disease and neuropathy, in children and adults with type 1 diabetes. Many doctors recommend that adults with type 1 diabetes and normal kidney function supplement with 200 to 600 mg of magnesium per day to maintain normal magnesium status; children with type 1 diabetes may benefit from a lower dose.

Vitamin B12, or cobalamin, is needed for normal functioning of nerve cells and is also involved in homocysteine metabolism. People with type 1 diabetes have an increased risk of other disorders that can affect their B12 status, such as autoimmune gastritis, celiac disease, and pernicious anemia.¹¹ Vitamin B12, taken at a dose of 1,500 micrograms per day for 24 weeks, has been found to reduce symptoms and disability due to diabetic nerve damage (neuropathy).¹² In a preliminary trial that included 544 participants with diabetic neuropathy, supplementing with vitamin B12 (in the form of methylcobalamin) along with folic acid (in the form of methylfolate) and vitamin B6 (in the form of pyridoxal-5-phosphate) for 12 weeks was associated with a 35% drop in symptom scores and a 32% drop in pain scores.¹³ A comparison trial in 100 subjects with diabetic neuropathy found injections of B12 were more effective than the commonly used pain medication, nortriptyline, for treating symptoms of diabetic neuropathy.¹⁴ A number of other studies have shown B12, alone and in combination with other treatments such as alpha-lipoic acid and prostaglandin E1, can be beneficial in those with diabetic neuropathy.^15,16 Oral vitamin B12 up to 1,500 micrograms per day is recommended by some practitioners.

People with type 1 diabetes may have impaired vitamin B6 metabolism, resulting in increased susceptibility to deficiency.¹⁷ Vitamin B6, along with other B vitamins, is critical for homocysteine metabolism and may thereby reduce their risk of vascular complications of diabetes, particularly diabetes-related kidney disease. Research in people with type 1 diabetes showed supplementation with B1, B6, and B12 lowered elevated homocysteine levels and improved kidney function.¹⁸ Vitamin B6 alone, at doses of 100 to 500 mg per day, also improved kidney function in a group of people with type 1 diabetes-related kidney impairment.¹⁹ In children with type 1 diabetes, taking 100 mg of B6 per day for eight weeks led to improvements in blood vessel function.²⁰ The benefits of B6 in people with diabetes may also be related to its apparent ability to prevent the formation of damaging advanced glycation end-products (AGEs).²¹