The amount of vitamin B12 required is very minute. As little as 0.1-0.5 µg per day (1-4 µg/week) is needed in a healthy adult. Stress, illness (especially involving the central nervous system), pregnancy, lactation, and rapid growth increase needs. The World Health Organization recommends 1 µg per day of vitamin B12. The RDA for adults is 2.4 µg of vitamin B12 per day, 2.6 µg during pregnancy, 2.8 µg during lactation, and proportionally less for children. Both have a significant margin of safety built into their recommendations.

Unlike other B vitamins, B12 is stored in the liver so daily consumption is not necessary. However, the normal uptake route of vitamin B12 is saturated very quickly so that doses larger than 5 µg are poorly absorbed and are not more effective than smaller doses. A second uptake route, diffusion, allows about 1% of any dose to be absorbed.

What happens if I donÕt consume vitamin B12? Though the requirements are very low, deficiencies among vegetarians have been noted. There are at least 10 case reports in the medical literature of infants suffering severe neurological damage when solely breast-fed by their totally vegetarian mothers. Most of the damage is reversible by vitamin B12 supplementation. Also, every study of vegan communities or populations has demonstrated low vitamin B12 concentrations in 40-90 percent of the group. Since many of these studies only measured serum cobalamin concentrations, they underestimated the number of people with metabolic deficiencies. This includes macrobiotic communities, natural hygienists, "living food" vegans, vegan Seventh Day Adventists, and followers of the Hallelujah Diet.

Our study revealed early signs of vitamin B12 deficiency in 26 of the 54 people tested, after following the Hallelujah Diet for as little as 2 to 4 years. Two important facts need to be noted. First, many, if not most, vegans have impaired vitamin B12 metabolism. This has been verified time and again in vegan groups. Second, metabolic deficiency of vitamin B12 can be detected after as little as 22 months on the Hallelujah Diet. While serum vitamin B12 levels may still be normal for several more years, the body, especially the central nervous system, may be deficient at the cellular level. 83% of the people in our study with metabolic vitamin B12 deficiency had normal levels of serum vitamin B12. These facts have not been widely appreciated by the vegetarian community.

Based on the published studies and our results, adequate vitamin B12 status of vegans cannot be taken for granted. Pregnant women, nursing mothers, infants, and small children are particularly vulnerable to B12 shortages. Ensuring adequate B12 is critical for normal neurological development and maintenance, with shortages resulting in permanent damage.

Deficiency of vitamin B12 leads to anemia and neurological abnormalities. Vegetarians' abundant dietary intake of folate masks much of the anemia due to vitamin B12 deficiency. So the first signs of vitamin B12 deficiency are neurological symptoms. These symptoms can include parathesia, especially numbness and tingling in the hands and feet, diminution of vibration sense and/or position sense (usually but not always occurring first in the ankles and feet), unsteadiness, poor muscular coordination with ataxia, moodiness, mental slowness, poor memory, confusion, agitation, and depression. Delusions, hallucinations, and even overt psychosis (usually with paranoid ideas) may occur.

By the time vitamin B12 deficiency can be detected clinically significant neurological damage has already occurred and an aggressive supplementation program should be begun with methylcobalamin. Symptoms caused by a deficiency can usually be alleviated by vitamin B12 supplementation. Healthy vegans with a healthy bowel flora should produce B12 in their small intestine. This may be the natural way God intended for us to receive our vitamin B12, but our study showed that this was not a reliable and sufficient source of B12.

All people produce B12 in their colon, but this is not available for the body since B12 is absorbed in the small intestine. Improving the bowel flora by using probiotic supplements (L. acidophilus, B. bifidus, etc.) may be helpful for supplying vitamin B12. However, our study revealed that daily use for 3 months of either of two different brands of probiotics was not sufficient to restore peopleÕs vitamin B12 status to normal.

Where do I get vitamin B12 in foods? The use of dulse, chlorella, nori, blue-green algae, spirulina, and fermented soy products has been promoted for their plant-based vitamin B12 content. However, when some of these products were analyzed for true cobalamin activity, they were shown to contain almost all analogues of vitamin B12 which are not active in the human body. In fact, some of these analogues interfere with normal cobalamin metabolism by competitive binding, resulting in poorer vitamin B12 status. Serum vitamin B12 levels may improve, while metabolic indicators deteriorate.

Nori and spirulina have both been shown to be ineffective at improving vitamin B12 status of children. It is not safe to rely on marine plant life or soy products for vitamin B12. We see then that dietary vegan sources of vitamin B12 are very sparse since plant foods do not contain vitamin B12 in appreciable amounts. There is some evidence that plants grown in soil fertilized with cow dung (rich in B12) contain higher levels of B12 within the plant.

Whether the reported B12 was true cobalamin and useful for people needs to be confirmed. Other vegan food sources include fortified breakfast cereals, fortified vegan products, fortified nutritional yeast, and dehydrated cereal grasses (like Barleygreen). The amount of B12 in Barleygreen has been shown not to provide adequate amounts of B12 for mature adultsÕ needs. Needs of infants and children are proportionally greater, so Barleygreen alone will not supply sufficient vitamin B12 for a child.

Nutritional yeast (Red Star Vegetarian Support Formula) is fortified with an adequate amount of B12 and is a good source of other B vitamins, trace minerals, and nucleotides as well. Many vegans have found this to be an acceptable and reliable source of vitamin B12.

What is the best supplemental form of vitamin B12? Sublingual tablets or low dose sprays are the best delivery forms of B12 supplements; swallowed tablets are not as effective. The best, most bio-available form of cobalamin appears to be methylcobalamin.30 This form of B12 (methylcobalamin) appears to be taken up by the body and used more efficiently than the more common cyanocobalamin.

Cyanocobalamin is typically made by chemical synthesis, or by isolation from animal products or waste. The manufacturer will report the source of the vitamin if asked.

Methylcobalamin is marketed by Enzymatic Therapy as "Bio-Active B-12" and is available from Hallelujah Acres. "Bio-Active B-12" is made from fermented plants and is an inexpensive, vegetarian product. 1/2 of a "Bio-Active B12" tablet twice a week should be sufficient for a healthy adult.

If I had consumed very little vitamin B12 in the last couple of years, I would take one tablet a day for ten days and then begin this maintenance program.

How do I know I am getting enough vitamin B12? A simple urine assay can be done through the mail with the Norman Clinical Laboratory, Inc. (Cincinnati, OH: 1-800-397-7408, $70). The urinary MMA assay is very specific for B12 and much more reliable than a serum B12 assay.31-35

If anyone has doubts about their B12 status this is the lab test to order. Your physician can order this commonly available test for you as well.

Conclusion There are many ways to get your vitamin B12 but you must get it in your diet or ensure that your body makes it. You will not have excellent health without it. Please take this information to heart, take precautions, and keep all of this in eternal perspective.