Could this also help people with PD ? There are substances in it that have been tested preclinical for PD.
The omega-3 fatty acids,uridine and choline look beneficial to PWP:

Impact of omega-3 fatty acids in Parkinson's disease

Restorative effects of uridine plus docosahexaenoic acid in a rat model of Parkinson's disease

CDP-choline: pharmacological and clinical review.

The only evidence I've seen for vitamin deficiency in PD is that for vitamin D though and I think the jury is still out on that.......

I shall look out for Souvenaid.......
Here is a more detailed description of Souvenaid's action: