B Vitamins

B vitamins refer to a group of water-soluble vitamins that play critical roles in energy metabolism, red blood cell production, nervous system function, and overall cellular activity. In horses, key B vitamins include thiamine (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), pyridoxine (B6), biotin (B7), folic acid (B9), and cobalamin (B12). Each B vitamin serves a unique biological function but often works synergistically with others in metabolic processes.

Horses typically synthesize most B vitamins through microbial fermentation in the hindgut, especially when consuming a forage-rich diet. However, in certain situations—such as high-intensity exercise, illness, antibiotic use, or limited forage intake—B vitamin synthesis or absorption may be compromised. Supplementation of B vitamins in commercial feeds or as separate additives may help support performance, recovery, hoof health (notably biotin), and appetite. Because B vitamins are water-soluble, excess amounts are generally excreted in urine, minimizing the risk of toxicity when fed appropriately.