B group vitamins are essential for the conversion of chemical energy that occurs within the muscle fibres. Under grazing conditions, the daily requirement of B Vitamins is produced by the micro-organisms in the large intestine. High grain intake lowers the intestinal PH with a resultant drop in vitamin B production.

A diet low in B Vitamins has shown to have an effect on athletic performance. Human studies have shown that when athletes were restricted to less than half of their daily requirement for vitamins B1, B2 & B6, a significant drop in performance occurred. Similar studies in equine athletes have shown that supplementing with vitamin B1 prior to competition improved performance by reducing the accumulation of lactic acid in the muscles.