Nature`s Way B-100 Complex B-Vitamins are essential to the conversion of cellular energy manufacture of hormones and proteins as well as maintenance of nerve structures. B-100 Complex is a combination of B vitamins used to treat or prevent vitamin deficiency due to poor diet certain illnesses alcoholism or during pregnancy. Vitamins are important building blocks of the body and help keep you in good health. B vitamins include thiamine riboflavin niacin/niacinamide vitamin B6 vitamin B12 folic acid and pantothenic acid. B-Vitamins are essential precursors of coenzymes involved in the conversion of cellular energy manufacture of hormones and proteins and repair and maintenance of nerve structures.