Please eat a light meal, drink plenty of water and have a good night's rest before donation. No fasting is needed before blood donation. Should you feel unwell on the day of donation, take a rest and consider postponing the donation until you feel better. Avoid drinking tea or coffee and consuming calcium-rich foods (milk, cheese, yogurt) with iron-rich meals or iron supplements. Tannins in tea, caffeine in coffee and calcium reduce iron absorption. Have your coffee or tea after your meals.