Hello Thanks for writing to HCM Biotin, known as vitamin B7 is considered as part of b complex. both can be combindly taken Being water soluble vitamins, Vitamin B complex is not stored inside the cells; rather they are excreted in the urine. Because of this, the risk for over dosage is not likely. However, when normal individuals do not need high amounts of vitamin B exceeding the tolerable limit, they are usually at risk for developing over dosage. Over dosage from the B vitamins causes osmosis of water from the interstitial space to the intravascular space in order to dilute the large doses and promote excretion through the urine. Symptoms of Vitamin B over dosage include: Increased thirst Flushing of the skin Excessive urination Diarrhea These symptoms are the compensatory mechanism of the body to eliminate the excessive vitamins through the bladder and bowels. Discuss this with your doctor and then decide Hope this helps Take Care.