I know can is poder in Spanish. But generally it would indicate the ability to do something rather than the permission.
You cannot drink.
No puedo beber.
The above sentence could imply: 1) that the subject is unable to drink, and 2) that the subject is forbidden to drink.
Does poder cover both the scenarios? Or is there a different word I should consider using to imply forbiddance?
The doctor says you cannot (are forbidden to) drink either milk or juice.
For the above sentence, would the following be the translation preferred by a native speaker?
Dice el doctor que no puedes tomar ni leche ni jugo.
If not, what would be the most natural way to convey the sense?
P.S. If there are regional quirks, I'd prefer Mexico-centric answers.