B vitamins (and folic acid) - particularly B2 (riboflavin), B6 (pyridoxine), and pantothenic acid - strengthen the immune system and may play a role in fighting the early development of malignant cells. In some studies, people deficient in riboflavin have developed cancer of the esophagus. In laboratory tests, folic acid, another of the B vitamins, has a protective effect against precancerous cells from the colon and cervix; and women with low levels of folic acid are more likely to develop cervical cancer. The B vitamins are available in a variety of foods. Citrus fruits are high in folic acid. Red meat, dairy products, asparagus, and broccoli contain riboflavin. Vitamin B6 comes from white meat chicken and fish, whole grain cereals, egg yolks, potatoes, and bananas. Vitamin B6 also helps brain chemical production which may help the body cope with anxiety and panic