B12 is an essential vitamin with roles throughout the body. It is needed for the development and maintenance of a healthy nervous system, the production of DNA and formation of red blood cells.
If the amount of B12 in storage is low to begin with, a deficiency can develop within a year, even more quickly in infants.
Natural plant sources are meager at best in B12, and the vitamin is poorly absorbed from them. Many strict vegetarians and all vegans, as well as infants they breast-feed, must consume supplements or fortified breakfast cereals to get adequate amounts.
Certain organisms, like the bacterium Spirulina and some algae, contain a pseudo-B12 that the body cannot use but may result in a false reading of a normal B12 level on a blood test. Despite claims to the contrary, laver, a seaweed, and barley grass are not reliable sources of B12.
Most multivitamins contain insufficient levels of B12, therefore the best bioavailability can be obtained via injection. When this water soluble vitamin is injected, it is absorbed and utilized 100% by the body…whereas GI absorption is a mere 60% or less. Injectable forms of B-vitamins can be found here.
In animal foods, B12 is combined with protein and must be released by stomach acid and an enzyme to be absorbed. Thus, chronic users of acid-suppressing drugs like Prilosec, Prevacid and Nexium, as well as ulcer medications like Pepcid and Tagamet, are at risk of developing a B12 deficiency and often require a daily B12 supplement.
Stomach acid levels decline with age. As many as 30 percent of older people may lack sufficient stomach acid to absorb adequate amounts of B12 from natural sources. Therefore, regular consumption of fortified foods or supplementation with 25 to 100 micrograms of B12 daily is recommended for people over 50.
Synthetic B12, found in supplements and fortified foods, does not depend on stomach acid to be absorbed. But whether natural or synthetic, only some of the B12 consumed gets into the body. Treatment to correct a B12 deficiency typically involves much larger doses than the body actually requires, usually by injection.
Free B12 from both natural and synthetic sources must be combined with a substance in the stomach called intrinsic factor to be absorbed through the gut. This factor is lacking in people with an autoimmune disorder called pernicious anemia; the resulting vitamin deficiency is commonly treated with injections of B12.
Others at risk of developing a B12 deficiency include heavy drinkers (alcohol diminishes B12 absorption), those who have had stomach surgery for weight loss or ulcers, and people who take aminosalicylic acid (for inflammatory bowel diseaseor tuberculosis) or the diabetes drug metformin (sold as Glucophage and other brands). Patients who take the anticonvulsants phenytoin, phenobarbital or primidone are also at risk. Women in general are at great risk, as those who are on birth control pills are depleting their sources of B-vitamins daily.
To find out how you can restore your B-vitamins, click here.