It depends, primarily on the amount of B vitamins you get from your diet and supplements.
That said, many people don’t regularly eat the foods that are highest in B vitamins, and vitamin B insufficiency can occur even in people who follow healthy diets.
It’s also very difficult to take enough B vitamins to harm your health, and it’s basically impossible to get too much from a combination of food and a moderate dose like you’ll find in Vitamin B Complex.