Vita Flex Pro Pure C supplement for horses, contains only absolutely pure vitamin C (ascorbic acid). No fillers of any kind have been added. Pure C supplement is a useful, highly palatable addition to equine feeding programs. Vitamin C helps support a healthy immune system. Pure C supplement is important in the production of collagen, GAGs and other critical connective tissue elements. Pure C is not only the purest available form of horse vitamin C, it's also your best value. Vita Flex Pro Pure C is a useful, highly palatable addition to equine feeding programs. Vitamin C is especially important for senior horses, those in heavy work, those with respiratory conditions, and any horse that has been stressed.