Please don't self-prescribe. - Also, don't think you can track results with a sample size of _one_. You have no control group and you have no way to establish patterns across many data sources. Vitamins and minerals have not been shown to be relevant to stuttering. In general micronutrients are important for our health, and in case you have a deficit, you should definitely get that looked at. Perhaps indirectly, it might affect your stutter. - But don't go experimenting like this. I think it might just add confusion, uncertainty, and anxious or neurotic thinking. That's not at all beneficial to add on top of what people like us already got going. Instead, please go see a speech therapist if you haven't already been. In fact, go see one again, even if you've been. These things take time and are not just brief interludes.