Vitamin B12 — Health Professional Fact Sheet
Click here for more information. ... Food Micrograms (mcg) per serving Percent DV* Clams, cooked, 3 ounces 84.1 1,402 Liver, beef, cooked, 3 ounces 70.7 1,178 Breakfast cereals, fortified with 100% of the DV for vitamin B12, 1 serving...