If looking into any supplement , ask your Dr. first.
Ive tried many, with no luck.Lots of people pushing miracles out there
Metformin can create a B12 deficiency, so a supplement is helpful.
I been taking vitamins D3 and
Vitamin c 500mgs for a while and also chromium and seems to help me maintain good readings for the last 4 years everyone is different though must say
Multi-Vitamin, Vitamin B Complex, Vitamin C (about 1,000 twice daily), Vitamin D2 is also good. I have taken supplements for most of my life. Vitamin C is known to help with blood sugars. Some believe Cinnamon helps blood sugar control but that isn't determined.