Friday, September 23, 2011

The Vitamin Every Plant-Eater Needs

Vitamin B12 protects the nervous system. Without it, permanent damage can result.  

It is generally found in all animal foods (except honey) and comes from the bacteria that grow on the rotting flesh of dead animals.

For those consuming a plant-based diet, it's important to know that there are no reliable, unfortified plant sources of vitamin B12 , including tempeh, seaweeds, and organic produce. The overwhelming consensus in the mainstream nutrition community, as well as among vegan health professionals , is that plant foods do not provide vitamin B12, and fortified foods or supplements are necessary for the optimal health of vegans, and even vegetarians in many cases.
Luckily, vitamin B12 is made by bacterial fermentation such that it does not need to be obtained from animal products.
Despite this, some vegan advocates still believe that "plant foods provide all the nutrients necessary for optimal health," and do not address vitamin B12 when promoting the vegan diet . Other advocates acknowledge the need for B12, but only as an afterthought. And still others emphasize that humans need only small amounts of B12 and that it can be stored in the body for years.

While true that, at the time they become vegan, some people have enough B12 stored in their liver to prevent overt B12 deficiency for many years, people often misinterpret this to mean that you only need to consume a tiny amount once every few years. Actually, to build up such stores, it takes years of consuming B12 beyond one's daily needs (unless you are using supplements which can build up stores more quickly). Some people do not have large enough stores of B12 to be relied upon even for short periods.

How Much B12 Should I Take?
If you have not had a regular source of B12 for some time, buy a bottle of 1,000 or 2,000 mcg B12 sublingual (i.e., dissolve under the tongue) tablets and take daily. It is okay to consume more B12 than needed. These tablets can be found at health-food stores and online. They are inexpensive and often flavored to appeal to children and adults.
 
More Tips on B12:
  • In foods, B12 is measured in micrograms (aka "µg" or "mcg"). 1,000 µg = 1 mg.
  • The daily recommended intake for B12 is 2.4 micrograms for adults.
  • Fortified foods: Amounts listed on a nutrition label are based on 6 µg/day. For example, 25% of the Daily Value = .25 * 6 µg = 1.5 µg.
  • The Food and Nutrition Board states that "Since 10 - 30% of older people may malabsorb food-bound B12, it is advisable for those older than 50 (whether vegan, vegetarian to meet their RDA mainly by consuming foods fortified with B12 or a B12-containing supplement." This could be due to decreased digestive enzyme production and/or decreased stomach acid after age 50.
  • Do not rely on any seaweed (e.g., algae, nori, spirulina), brewer's yeast, tempeh, or "living" vitamin supplement that uses plants as a source of B12.
For more information on the daily recommended intake of B12 for different age groups,
check out: www.veganhealth.org
(This site and adapted article are from Jack Norris, registered dietician and vegan nutrition expert)

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