@burcinc-- I've actually been taking 800mg of ALA daily and I'm diabetic. I agree that diabetics need to be careful with this supplement and start off at the lowest possible dose and check their blood sugar. That's what I did and I have gone up to 800mg without side effects.
It can reduce blood sugar in some diabetics but not all. It hasn't done that with me. The only issue I have with it is upset stomach if I take ALA on an empty stomach. If I take it with my meal or afterward, I have no problems.