For vegetarians, B12 fortified breakfast cereals give 100% of the recommended daily. Dietary supplements also provide an animal-free source, and while it acts fundamentally the same as natural sources, it is not readily absorbed. Research shows that only a very small fraction of the B12 provided in pill form actually gets used; the rest gets converted into incredibly bright yellow urine. For individuals who have difficulties absorbing through the digestive tract, injections are available.
Deficiencies in B12 result in symptoms of fatigue, headaches, depression, and weight loss, among others. This is easily seen on the tongue, which can turn pale, swell, and bleed.
For more information: http://ods.od.nih.gov/
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