What if i take biotin and a multivitamin together?

Often too much: In the absence of known deficiency, multivitamins are unnecessary. Common deficiencies are vitanin d in people who don't get much sun exposure and vitamin B12 in vegans who don't supplement. Multivitamins are now increasingly seen as unhealthy if not needed. Check with doctor before taking any. Get biotin from nuts, carrots, and berries.