Some people it helps, some it doesn't.

I think it helps some who might be diabetic or prediabetic because it supports B cell function in the pancreas and thus insulin secretion/resistance.

I don't have diabetes nor am I prediabetic though I do have insulin resistance.

I gain weight rapidly in winter and am able to lose weight during summer. While supplements don't cause me to lose weight during winter I do feel that I do not gain weight as rapidly now with full D levels as I did in past winters.