For managing type 2 diabetes, several dietary supplements have been studied for their potential effects on glucose control and insulin sensitivity. Here are some that have shown promise:

1. Chromium: While it is widely used, chromium supplements have shown minimal benefits in managing blood sugar levels, and large doses can be harmful[^1].

2. Magnesium: Some studies indicate magnesium may help control blood sugar, but evidence is mixed, and excessive intake can lead to adverse effects like diarrhea[^1].

3. Cinnamon: There is some evidence that cinnamon might lower fasting blood glucose levels, but it hasn't been proven to lower A1C levels significantly to ensure overall better glucose management[^2].

4. Vitamin D: Low levels of vitamin D have been linked to an increased risk of diabetes and cardiovascular diseases, though supplementation should be considered based on individual deficiency tests[^3].

5. Berberine: It's an herbal supplement that has been shown to improve insulin sensitivity and reduce blood sugar levels[^4].

6. Antioxidant Vitamins (A, C, E): People with diabetes often have deficiencies in these vitamins, and supplementation may help manage oxidative stress, though evidence for comprehensive diabetes management is limited[^5].

7. B Vitamins: Particularly vitamins B9 (folic acid) and B12. People on metformin, a common diabetes medication, often need supplementation due to absorption issues[^3].

It's crucial for individuals with diabetes to consult healthcare providers before starting any supplement to consider potential interactions and ensure they're safe based on personal health needs[^1][^3].