iO Cider Vinegar 8percent with Vitamin B1 and Garlic helps build immunity-fighting bad bacteria, and promote good bacteria. Used as a regular part of feeding, it is believed to assist with arthritis and joint conditions. Apple cider vinegar helps acidify the stomach for optimum digestion. As an natural insect control, Apple Cider Vinegar has been known to cause thiamine (Vitamin B1) to be excreted through the skin, repelling flies and mosquitoes. Optimum levels of B vitamins (particularly B1) in the body seem to discourage bugs.