What is vitamin b100 complex good for and can anyone just take it?

Vitamins: B-complex vitamins are water soluble vitamins that are found in normal foods, and are already part of your healthy diet. Unlike some vitamins and supplements, these won't hurt you even if taken in large doses - but you should know that no one has demonstrated health benefits to taking this or other vitamin supplements, unless your diet is severely deficient.

B6: In general B vitamins are very benign and excesses are easily excreted from the body. However, be careful with B6. Megadoses of B6, above 400mg daily, over time can cause neuropathy.