I.e, vitamins from big pharmacies. Are there kashrus issues? Must they be certified?
Q: Can one assume all vitamins in general are kosher, year round, including chewable and gummies?
IMHO that would seem to suffice for your second question. But your first question is slightly different than this question that was phrased "Can one assume.." (i.e. in general; the product doesn't present itself as say, Bacon flavored gummy; maybe there's an issue there?).