The Overlooked Epidemic of Vitamin B12 Deficiency
Vitamin B12 is the largest and most complex of the water soluble B vitamins and the only vitamin that contains a trace element, cobalt, which gives it a red color and the common name cobalamin. As a coenzyme, vitamin B12 plays a crucial role in the healthy functioning of the body including energy metabolism, production of DNA and RNA, brain and nervous system function, the formation of red blood cells, and proper functioning of the cardiovascular, reproductive and immune systems. Though adults need only 3 to 6 mcg of B12 per day for optimum health, dietary intake of B12 should exceed that amount due to the complex process required to assimilate and metabolize this essential nutrient. Ingested B12 that is not immediately used by the body is stored in the liver and to some degree the kidneys and other body tissues. Any excess is harmlessly passed out of the body as waste. In the absence of daily B12 intake, B12 stores can last for several months to years before deficiency becomes apparent. The human active forms of vitamin B12 are only available from animal sources where it is produced by intestinal bacteria or supplements from cultured microorganisms. Liver has the highest content of B12 (100 mcg per 100 g), followed by kidney (55 mcg), oily fish (4-20 mcg), shellfish (4-12 mcg) white fish (0-2 mcg), red meats (1-3 mcg), white meats (0-2 mcg), eggs (2.5 mcg), and dairy products (1-1.5 mcg). Butter has only trace amounts of B12. Plant forms of vitamin B12, called B12 pseudo analogues, which are concentrated in foods such as spirulina, blue-green algae, chlorella, seaweeds, tempeh and nutritional yeast, cannot be utilized by the body. In fact, in large amounts they [...]