Vitamin B12 and folic acid blood testing help doctors diagnose central nervous system disorders, anemia, and malabsorption syndromes. B12 and folic acid also play an important role in energy level, muscle strength, and memory. Because B12 and folate are derived solely from dietary intake, such as egg yolks, beef, poultry, and fish, many people are deficient in these important vitamins.
This test may be done fasting or 2-6 hours after eating. Both ways provide valuable information, though 2-6 hours after a meal provides a more realistic assessment of the state of your blood in everyday life. Stay hydrated and take your medications as prescribed.