Studies support the following nutrients improve blood sugar stability:
Chromium: 200 - 1000 mcg per day. 1000 mcg offered better results.
Biotin: 9-16mg (9,000 - 16,000 mcg) per day improved glycemic control in some type 1 and 2 diabetics.
Alpha Lipoic Acid: 600mg per day. dosages above 600mg were not more effective.
Magnesium: 300mg per day improved diabetic neuropathy in 39% of cases after 5 years.
Vitamin D: In people whose serum Vitamin D levels were low, < 25 ng/ml (OH)D, vitamin d supplementation improved insulin secretion, insulin resistance, and/or glycemic control.