“100 years ago a new word in medicine was invented: vitamin. This year the world will spend over $100,000,000,000 on vitamins and supplements. ($40,000,000,000 in the US.) Dr. Derek Muller takes us on a world spanning investigation of vitamin science and history, asking how do we decide whether to take vitamin supplements or not?”
If I took any more supplements, my pee would glow-in-the-dark.
Cobb Liver Oil launched the vitamin industry.
There have been 10 Nobel prizes awarded in vitamin science.
In 1994 the U.S. Congress passed a law forbidding the testing of supplements for safety and effectiveness.
Hundreds of thousands of children go blind for lack of vitamin A, but too much can be toxic.
Vitamin D is critically important and the world is in the midst of a vitamin D deficiency causing much illness, but too much can be toxic.
Vitamin levels needed for optimal health is person specific, which explains why such a wide variation in the dosing of B-1 on HU.
Vitamins in food are better than vitamins as pills for the same reason that levodopa in Mucuna Pruriens is better than levodopa as a pill.
Etc., etc.
List of PD Supplements and medications
levodopa or not levodopa 
Vitamin D - heads up
B Vitamins and the Brain: Mechanisms, Dose and Efficacy
Comprehensive supplements list (when to take and with what)? Not just for PD.
