Can someone actually overdose from vitamin b6?

Not exactly but...: This depends on what you mean by overdose. I think of overdose as a single high dose causing harm, in which case taking a large single dose of b6 will not cause harm.However, taking high doses of b6 daily for months (usually at least 1000 mg but in some as low as 200 mg)can cause toxicity symptoms, most commonly peripheral neuropathy, also headaches, fatigue & irritability, reversible on stopping b6.