' Well it'd be idiotic to call them medicines then otherwise they'd be regulated by the MHRA gov.uk/government/organisations/medicines-and-healthcare-products-regulatory-agency I stated "classed as a food product". This would be their legal definition and its why they can be advertised suggesting bold claims without any scientific evidence. OPs post isn't bad for this. I didn't say they were food
In addition to the above, I decided why not provide some evidence. I am way past the "stigma" of mental health issues. Around 10 years ago I developed a particularly bad and atypical presentation of obsessive compulsive disorder (OCD) which did not respond to medication. First line treatment for OCD is SSRI anti-depressants. I gave every single one a good try with at best very mild improvement and at worst, no improvement at all but terrible side effects. Doctors would not give me tricyclic (an older kind of) anti-depressants and basically told me there is no further help. 5-6 years later, I discovered that massive (relatively to the daily requirement) doses of niacinamide knocks it dead in it's tracks. I discovered this as the result of a documentary about orthomolecular medicine. My GP knows that I take it and why. This is important because there have been very rare cases of liver damage from very high doses of niacin. For anybody who doubts, reduction of the dose of niacinamide results in a return of symptoms quite quickly.
When you are deficient, taking the RDA of a nutrient will still leave you deficient. You need bigger "loading" doses to restore levels, then you can start taking the RDA again (unless it is identified you require more).
I'm not disagreeing with you there.
The food standards agency regulate supplements. food.gov.uk/business-guidance/food-supplements