Vitamin B6 is a water-soluble vitamin that is widely available in fish, chicken, some fruits and vegetables, and wheat germ. B6 may be decreased with malabsorption and inflammatory disease of the small bowel, as well as alcoholism and diabetes mellitus. Deficiency of this vitamin has been implicated in a wide variety of clinical conditions such as impaired red blood cell function, amino acid metabolism, and immune function. Additionally, in adults, elevated serum homocysteine levels due to vitamin B6 deficiency may increase the risk for arterial plaque. Fasting is not required for this test. Take all medications as prescribed.