The best time is 1, twice a day, once at noon and once at night. Vinegar is not only a condiment, but also a health food. In addition to a large amount of acetic acid, vinegar also contains calcium, iron, gluconic acid, lactic acid, glycerol, fatty acids and salts. In terms of eating, vinegar can dissolve calcium and iron in food, which is convenient for human body to absorb and protect the nutrients in food from being destroyed.