Is it dangerous to get too much b vitamins each day?

For some of them. Most of the b vitamins must be replenished regularly, since any excess is excreted in the urine. But some, if taken in excess can cause problems: b3—3000 mg nicotinamide or 1500 mg nicotinic acid/day can cause nausea, vomiting, signs of liver toxicity. B6— more than 1000 mg/day is associated with peripheral sensory neuropathy. B9 excess can mask B12 deficiency. B12 excess may cause rash.