A restriction or prohibition that has survived almost 50 years (1975-2020) without any scientific reason since levodopa was linked to carbidopa or benserazide.

No vitamin B6, no dopamine. The famous enzyme that converts levodopa to dopamine needs vitamin B6 (its active form, pyridoxal phosphate).
Of course, always with the supervision of the neurologist, who will adapt the general recommendation to each individual case and with the right amount (in general, up to 25 mg, as recommended by neurologists Ahlskog, Marjama-Lyons, Siniscalchi...). You can check it out on the package insert of your levodopa medicine.

Renowned neurologist Dr. Eric J. Ahlskog, acknowledges in his books that he recommends to his Parkinson's patients 25 mg of B6, 2 mg of B9 and 2000 mcg of B12 to control the dangerously homocysteine in Parkinson's patients and more in those taking levodopa. "Interestingly", the upper limit indicated on the package inserts for levodopa with carbidopa, benserazide or levodopa-carbidopa with entacapone.

I hope you find it useful.

Jesus Marquez