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Vitamin B12: Are You Getting It?

January 30, 2002 | 49,584 views

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Oral B12 Even for People with Malabsorption

Intramuscular injections (IMI) of B12 are the typical way to treat B12 deficiency. The injections can be painful and expensive. Kuzminski et al.56 (1998, USA) studied 33 newly diagnosed B12 deficient patients (almost all had malabsorption) to receive cyanocobalamin as either 1 mcg intramuscularly on days 1, 3, 7, 10, 14, 21, 30, 60, and 90, or 2000 mcg orally on a daily basis for 120 days.

The higher serum B12 and lower serum MMA levels at 4 months in the oral group were significantly higher than the injected group. Kuzminski et al. concluded that 2000 mcg/day of oral cyanocobalamin was as effective as 1000 mcg injected intramuscularly each month, and may be superior.

Delpre & Stark28 (1999, Israel) studied patients with B12 deficiency to see if B12 can be absorbed by holding a tablet under the tongue, known as sublingual. 5 patients had PA, 7 were vegetarians, and 2 had Crohn's disease (which can prevent the absorption of B12 in the ileum).

The patients held two 1000 mcg B12 tablets (equaling 2000 mcg/day) under their tongues for 30 minutes until completely dissolved. This was done for 7 to 12 days. Average sB12 levels went from 127.9 " 42.6 to 515.7 " 235 pg/ml. All the patients' sB12 normalized.

There were no side effects and all patients preferred this to IMI. Bodamer & Scaglia10 (1999) pointed out that in addition to the B12 absorption problems listed in Delpre & Stark's28 study, some people have inborn errors in B12 metabolism and people such as this might not benefit from oral cyanocobalamin therapy. Such people will need more careful medical attention.

Norberg75 (1999, Sweden) points out that investigations in the 1950s and 60s showed that oral B12 is absorbed by an alternative pathway not dependent on IF or an intact distal ileum. Approximately 1% of an oral dose in the range of 200-2000 mcg/day was absorbed by the alternative pathway. Based on this research, oral treatment, rather than IMI, has been in use for the majority of B12 deficiency cases in Sweden since the early 70s.

In a literature review encouraging the use of oral cobalamin therapy over injections for patients with PA, Lederle58 (1991) reported that Swedish investigators recommend 2000 mcg B12 twice a day or injections to replenish B12 stores of patients with PA. After initial therapy, doses of 1000 mcg/day appear to be enough.58
Please note that the above doses are for people with B12 malabsorption. People without malabsorption problems or current B12 deficiency should only need doses much closer to the RDA.

Fortified Foods

The "Daily Value" for B12 found on cereal boxes, etc., is based on the 1968 RDA of 6 mcg. So, to figure out how much B12 is in a serving of a particular food, multiply the percentage listed on the box by 6 mcg.49 For example, if the nutrition panel on a cereal box lists the B12 amount to be 25%, multiply 6 mcg by 25%: .25 * 6 g = 1.5 mcg (in one serving of the cereal).

Where Do B12 Supplements Come From?

Vitamin B12 is obtained through bacteria cultures. More details will eventually be published online at http://www.veganoutreach.org and in updated versions of this article.

Vitamin C

Vitamin C in doses of 500 mcg or more taken with meals or within one hour after a meal, may diminish B12 availability or destroy the B12.35


Calcium is necessary for the absorption of B12. Adequate calcium can be obtained from collards, kale, turnip greens, mustard greens, radish greens, and broccoli, but not from spinach, chard, or beet tops (though these are good sources of other nutrients).19 If calcium supplements are necessary, use calcium citrate, lactate, or gluconate. Calcium carbonate cannot be absorbed and utilized until it is converted to calcium chloride in the stomach.19 Using stomach acid to convert it will interfere with B12 absorption and digestion of foods.19

Correcting & Preventing Deficiency in the Elderly

Oral B12 from 6-300 mcg is necessary to correct B12 deficiency in the elderly.35
Elderly people (vegan or not) should consider getting a Schilling test to make sure they are still making enough IF. If you fail a Schilling test, you will need to take B12 either sublingually28 or through IMI.

Note: Even if an elderly person passes a Schilling test, they still might not be absorbing B12 from food because they may lack the stomach acid or enzymes49 required to break the protein-B12 bond found in food (a Schilling test uses non-bound B12).47

Approximately 2% of older adults do not produce enough IF, while 10-30% of people over 50 may have protein-bound B12 malabsorption.49 People who pass a Schilling test but lack gastric acid must take supplements. However, this is possibly not relevant to vegans since vegans get their B12 through supplemental sources where B12 is not protein-bound anyway.

Herbert48 (1994) suggests that serum B12-TC2 be measured every 5 years starting at age 55.

Intestinal Bacteria

A study in the 1950s in England was performed where vegan volunteers who had B12 deficiency (megaloblastic anemia) were fed B12 extractions made from their own stools and it cured their deficiency.

In reporting the study, Herbert47 (1988) said it proves that the colon bacteria of vegans produce enough B12 to cure a deficiency, but that B12 produced by bacteria in the colon is excreted rather than absorbed.

B12 deficiency among vegetarian Indians has been found with relatively high frequency in Indian immigrants in England, whereas it is uncommon among native Indians with identical dietary patterns.2 Healthy Indian subjects have a more extensive amount of microflora in their small intestines than people in the West.2

Albert et al.2 (1980) measured B12 production of bacteria in the small intestine of people in India using various microbiological assays. They determined that some true B12 was produced by members of the bacteria genera Klebsiella and Pseudomonas.

Confirmation using chromatography and bioautography showed a molecule with similar properties of cyanocobalamin. They speculated that since there is some free IF in the ileum (see paragraph below), it would pick up this B12 (while leaving analogue behind) and could then be used by the body without interference from the B12 analogues produced by intestinal bacteria.

Albert et al.2 also speculated that when Indians migrate, their upper intestinal bacteria change to those characteristic of people in Western countries with little or no resident flora in their upper small intestine.

An article with no author in Nutrition Reviews76 (1980), suggested some reasons why Indian immigrants in Britain had more B12 deficiency than Indian natives: a) in India, the water is contaminated with various microflora, including those from human and animal feces; b) The practice of defecating in open fields and lack of proper sewage; and c) the mode of toilet hygiene where water is used instead of toilet paper. Baker7 (1981) responded by pointing out that a lack of B12 in the bile (from low B12 stores), or low B12 intake, frees up IF in the ileum which then allows IF to bind to any B12 produced by bacteria in the small intestine.

Herbert45 (1984) reported that 85% of human feces B12 is analogue and that human intestinal bacteria are a major source of B12 analogue. When someone loses the ability to secrete stomach acid, bacteria can colonize the stomach producing large amounts of B12 analogue. The analogue can block the absorption of true B12 by blocking the B12-IF receptor sites. Some analogue may be absorbed and may block B12 metabolism in tissues.

Bacteria in the oral cavity does produces small amounts of corrinoids. However it has not been determined whether it is active or analogue.64

Organic Food as a B12 Source

Robbins et al.83 (1950, New York Botanical Gardens) used the bacteria Euglena gracilis var. bacillari as a microbial bioassay for vitamin B12 "or its physiological equivalent". A considerable proportion of bacteria and actinomycetes (molds) in the soil were found to synthesize "B12". B12 was also found in the roots of plants (.0002-.01 mcg B12/mcg of fresh material). Some stems had some B12, but leaves and fruit generally did not. B12 was also found in pond water and pond mud. It should be noted that this one paragraph report has often been cited in vegan literature for the amount of B12 found in the soil.

Herbert47 (1988) reports that in 1959, some Iranian vegans were found to be growing plants in night soil (human manure). The vegetables were eaten without being carefully washed and the amount of B12 was adequate to prevent deficiency.

Some B12-producing bacteria grow in the nodules and on the roots of some beans in India.47

The availability of B12 for animals is dependent on cobalt levels in the soil. Citing an article from the Annals of the New York Academy of Science (1964;112:735-55), Crane et al.18 (1994) point out that some soils in Australia, New Zealand, Britain, Canada, Eire, Germany, Holland, Kenya, Poland, South Africa, Sweden, Russia, and the USA have insufficient cobalt for adequate B12 formation. (Plants take up cobalt from the soil which is then eaten by animals.89) Crane et al. state, "This is a major concern of ours because vegans commonly seem to hold to the concept that all essential nutrients will be supported in foods from non-animal sources. They fail to realize that plants can grow readily in soil that is too low in cobalt for bacterial action to supply animals with sufficient B12."

Mozafar & Oertli70 (1992, Switzerland) added cyanocobalamin to the soil of soybean plants in amounts ranging from 10-3200 mol/l. Using an IF radioassay, 12-34% of the B12 was absorbed and the higher the amounts of B12 added, the higher the percentage absorbed.

Mozafar concluded that the B12 was stable in plants in the short term. 65.8-86.5% of the absorbed vitamin remained in the roots and the rest was transported to the various parts of the shoots, mainly the leaves. Mozafar points out that the concentrations of B12 in the soil used in this study were many times higher than the reported vitamin concentration in soil solution [.003 mol/l as measured by Robbins83 (1950) above].

Mozafar71 (1994, Switzerland) reported that there has been a relatively consistent finding of more B vitamins in food grown with organic rather than synthetic fertilizer. He then studied how the B12 levels in plants are affected by adding cow dung to the soil. A radioassay using pig IF was used to measure the B12. The study looked at the B12 content of both plants and soil:

Does this mean that organic foods are a reliable source of B12?

Since B12 is water-soluble, and in plants tends to be in free form (i.e., not protein-bound, as Mozafar points out), much of the B12 might diffuse into the water and be discarded during cooking.

And because at least one study indicates that IF is not completely reliable,21 it would be prudent not to rely on any sort of B12 in organic plants until research has verified that it is true B12 and consistently found in a wide range of organic food in the U.S.

Mozafar's study seems to indicate that foods grown in cow manure could contribute small amounts of B12 to the diet in at least some instances. But these amounts are far short of what is ideal. Additionally, the vegan movement is typically not aiming for a world where there are enough cows to produce a significant amount of manure for fertilizer. Because of this, vegans should probably focus their attention on non-animal-manure sources of B12.

B12 in Seaweeds, Tempeh, and Other Plant Foods

There has been a long history of misconceptions about which, if any, plant foods are good sources of B12. Much of this stems from the use of unreliable methods that measure B12 analogue rather than B12. Other confusion stems from the fact that bacterial contamination may occur in some foods in certain countries but not in others. Below is a survey of the scientific literature on B12 in plant foods, some of which appears to have contradictory information.

Herbert & Drivas43 (1982, USA) reported an analysis of 3 brands of spirulina sold in health food stores. 80% of the B12 shown with the microbiological assay that at the time was used by US Pharmacopoeia (L. leichmanni) was shown to be analogue using IF.

van den Berg et al.101 (1988, Netherlands) analyzed the B12 content of various foods using IF as well as microbiological assay. There was no measurable B12 found using either method for fermented foods such as tempeh, tofu, shoyu, tamari, rice miso, barley miso, amesake rice, or umeboshi prunes.

Some B12 (0.02-0.5 mcg/100 mcg) was found in barley malt syrup, sourdough bread, parsley, and shitake [presumably shiitake mushrooms]. Some algae were rich in B12 using IF, including spirulina, kelp, kombu, wakame, dulse, and various species of nori (which contained 12.0-68.8 mcg/100mcg; a very large amount).

Miller et al.68 (1991, USA) found that B12 status appeared to be unrelated to consumption of several vegetarian foods, including wakame, kombu, other sea vegetables, tempeh, or miso in macrobiotic children and adults.

Dagnelie et al.21 (1991, Netherlands) say, "It seems unjustified to advocate algae and other plant foods as a safe source of vitamin B12 because its bioavailability is questionable".


Wakayama et al.104 (1984) measured the amounts of B12 in insects using an IF radioassay. They determined that bacteria in the insects' digestive tracts were responsible for the production of the B12. Some insects, such as the housefly, had no detectable B12.

However, other insects had some B12, such as one cockroach species (.004 mcg/mcg). 5 termite species produced large amounts of B12 (.455-3.21 mcg/mcg). This could help explain how primitive humans could have obtained B12 without needing to rely on large amounts of meat.


During pregnancy, B12 is actively transported by the placenta to the fetus, which can reduce the mother's stores of B12 if she has no B12 in her diet.55 In contrast to the NV adult's normal storage of 3000 mcg B12, newborn infants (of mothers with normal B12 stores) have body stores of only 25 mcg.

Studies have shown that colostrum and/or milk during the first week of life contains larger amounts of B12 (as much as 2421 pg/ml) than later milk.94 B12 stores in infants at birth are normally adequate to last the first several weeks of life,55 after which time they must get it from breast milk or other sources. Serum B12 levels of normal infants decrease progressively until 6 months,64 after which they start to increase again.

If the mother is B12 deficient during pregnancy, the baby may have low B12 and some have developed clinical signs of deficiency as young as 2 months of age.103 At birth these newborns typically have higher sB12 than their mothers and usually show no deficiency symptoms.64 Infants of vegan mothers have almost no B12 in their enterohepatic circulation.48

Infants of Vegan Mothers Who Do Not Use B12 Supplements

Since 1980, there have been many reports of B12 deficiency in vegan mothers' infants whose main or only food is breast milk. This tends to happen only when the mother does not supplement her own or the baby's diet with B12. In many cases, the mother belongs to a subculture which does not believe in supplementation.

Unfortunately, lack of B12 in the mother's diet during pregnancy has been shown to cause a severe lack of myelin in nerve tissue.61 The following are studies reported between 1981 and 2000 in which infants of vegan mothers have suffered from B12 deficiency. In all cases, the infants are healthy until about 6-12 months of age after which they fail to thrive and show developmental regression.

They are lethargic and lose their ability to use their muscles adequately and sometimes cannot sense properly. They normally have macrocytic anemia. For these studies, I will only list unusual circumstances surrounding the case. Unless otherwise noted, these infants were exclusively breast-fed by mothers who did not take supplements.

Davis et al.27 (1981, USA) pointed out that macrocytic anemia in childhood is uncommon and usually due to nutritional deficiency rather than to congenital metabolic disease. Davis reported an infant admitted to the hospital with mild heart failure and other symptoms of B12 deficiency. He had undetectable sB12. He had elevated uMMA and Hcy. The mother's sB12 was 278 pg/ml. He was given IMI of B12 and by day 28 all blood values had returned to normal. His diet was then supplemented with 50 mcg B12 twice per week. No further follow-up was noted.

Close17 (1983, Dominica) reported a 12-month-old infant of Rastafarian vegan parents. His development had regressed, and he had frequent vomiting and extreme tiredness. 5 mcg of oral folate was given for 2 weeks, but did not solve his problems. Oral B12 was then given for 42 days and the child stopped vomiting, regained his energy, and his developmental regression disappeared. The child's mother was healthy. Close suspected the mother had sufficient B12 for herself, but not enough for her breast milk.

Hellebostad et al.41 (1985, Norway) reported a 2-year-old girl who was vegetarian except for small amounts of milk, eggs, and cod liver oil. She was also taking a calcium supplement. She had signs of rickets, low calcium and low phosphate (caused by lack of vitamin D), low protein levels, and B12 deficient neurological problems which had been slowly progressing since age 1. Serum B12 was 54 pg/ml. She was treated with vitamin D, calcium, oral iron, and B12 injections. In 2 weeks, her signs of rickets and B12 deficiency had resolved. Her mother also had low B12 (149 pg/ml) and was pregnant. She was given B12 injections and a multivitamin and she and the baby have both done well.

Sklar91 (1986, USA) reported a male infant with B12 deficiency. The parents had been vegan for 6 years. 2 weeks prior to admission the parents took him to a naturopath who suggested they take him to the hospital. The parents refused this advice but the mother agreed to begin taking multivitamins. The child's hands, feet, and abdomen began to swell and they took him to the hospital. He was given a blood transfusion and a 1000 mcg B12 injection. 4 more 1000 mcg injections were given on succeeding days. Within 48 hours, the patient improved and was discharged on the 4th day. The child and mother were given 50 mcg B12 to take for the next month, followed by multivitamins for the next 4 months. The mother refused to allow her breast milk or blood to be examined. 6 months later, the infant was doing much better.

Gambon et al.32 (1986, Switzerland) reported an identical twin with B12 deficiency. The mother had been vegan for 7 years before the birth of her twins. At 8 months, one twin started to become apathetic with deteriorating motor skills. By 11 months, he was admitted to the hospital. Treatment with B12 (three 500 mcg B12 injections in 6 days), which resulted in a full recovery and he was discharged with an oral vitamin supplementation containing 6 mcg B12 daily.

The mother refused any further controls and did not follow the advice to give iron orally. The child was readmitted 2 months later showing blood values consistent with iron deficiency. The infant was put on an oral iron supplement and blood value returned to normal within 1 month. No relapse of B12 deficiency was noted after oral supplementation. The other twin was not reported to have any problems.

Stollhoff & Schulte96 (1987, Germany) reported an 18-month-old boy whose mother had been vegan for 4 years previous to the child's birth. The child had been breast-fed with additional fruits and vegetables. He had a progressive neurological disorder starting at 6 months. The boy's sB12 level was 63 pg/ml, and the mother's sB12 was 84 pg/ml. B12 therapy was started at 1000 mcg/day.

After 5 weeks, the anemia disappeared and the neurological condition dramatically improved. However, at 26 months, the boy was functioning at a 12-month-old level and still had exaggerated reflexes. The child continued to make psychomotor progress. In contrast to the literature, there was no increased MMA in blood or urine. Stollhoff thought this was possibly due to the fact that the patient had received small amounts of animal products prior to hospital admission.

Bar-Sella et al.8 (1990, Israel) reported having examined an infant of a vegan mother who had severe neurologic damage which was partially corrected at the age of 14 months by B12 therapy.

Michaud et al.66 (1992, Canada) reported an infant of a vegan mother both of whom had low B12. This case was notable because urinary MMA was detected at 3 weeks, indicating a compromised B12 status, which was then corrected before problems developed.

Graham et al.34 (1992, Australia) reviewed the clinical findings in 6 infants with nutritional vitamin B12 deficiency seen during the last 10 years at Prince of Wales Children's Hospital in an attempt to obtain long-term neurologic follow-up.

There was a consistent pattern in B12-deficient infants: irritability, anorexia, and failure to thrive were associated with developmental regression and poor brain growth. 3 of the 6 patients were infants of vegetarian mothers. 2 infants had pernicious anemia and one infant's mother had pernicious anemia. 2 of 4 patients who qualified for long-term review had a poor intellectual outcome.

One whose mother had been vegetarian had borderline intellectual development at age 5.

Kuhne et al.55 (1991, Switzerland) reported an infant of apparently healthy parents who had been vegan for 10 years. The infant was admitted for suspected malnutrition. Upon admission, examination revealed partial atrophy of the optic nerve. B12 was very low in both the infant's and mother's serum. The infant's Hcy levels and MMA were high. The mother's uMMA was also slightly raised and her breast milk was low in B12 (85 pg/ml).

The infant's intake of B12 was estimated to be 0.05-0.07 mcg/day. B12 was immediately initiated with IMI of 1000 mcg for 4 days and 1000 mcg orally on the 5th day. All muscle problems vanished after 10 days. The patient was discharged and the parents were given an oral vitamin B complex including B12. The parents agreed to add eggs and dairy to the child's diet [which is unnecessary]. By the 15th month, the child's physical measurements and laboratory values were normal. No further follow-up was reported.

Lovblad et al.61 (1997, Switzerland) reported a case of a 14-month-old girl of strictly vegetarian parents with a minimal intake of dairy. Her B12 level was 124 pg/ml. MRI of the brain revealed severe brain atrophy. The patient was treated with a multivitamin, iron, folic acid, trace elements, and 1 ng B12 every other day. [The 1 ng was possibly an error. It was more likely 1000 mcg.] She responded well and at 20 months could sit alone, crawl, walk with help, and speak simple words.

von Schenck et al.103 (1997, Germany) reported a 14-month-old, male infant with severe neurological abnormalities. His mother had been vegan for 6 years, and vegetarian for 8 years previous to that.

She ate a high proportion of raw foods. The infant was exclusively breast-fed for 9 months and then ate small amounts of fruit. He had developed normally during the first 10 months. He gradually became inactive after 12 months. He was comatose on admission to the hospital. Serum B12 was undetectable with a high uMMA (32.4 mmol/g creatinine). He had severe brain atrophy. He was injected with 250 mcg B12, and then received oral treatment of 25 mcg B12/day, along with a supplemented soy formula.

He regained consciousness in hours. By the third day he was able to walk, eat, drink, and was discharged. His parents kept him on a vegan diet, but agreed to give him soy formula and oral B12 supplements. A cranial MRI 10 weeks later showed all structural brain abnormalities had disappeared, but he continued to show neurological damage.

At 2 years of age, he still showed psychomotor retardation, was very agitated, and had poor concentration. He could not speak any words. His 3-year-old sister had low serum B12 levels (139 pg/ml). The mother had serum B12 of 149 pg/ml which became normal after taking oral supplements.

Although vitamin B12 supplements have been shown to result in rapid lab value improvements in breast-fed infants of vegan mothers suffering from B12 deficiency, concern has been raised about their long-term development.

von Schenck103 (1997) reviewed 25 reports of infant B12 deficiency which had appeared in the scientific literature. Of the 25, 13 had vegan mothers (9 of which occurred since 1979 and are included here). Of the 7 vegans that were followed for a certain amount of time, 5 still had abnormal neurological development at their respective final follow-up at 26 months, 26 months, 2 years, 5 years, and 12 years. 2 were normal at their respective final follow-up at 13 months and 2 years. "Efforts should be directed therefore to preventing deficiency in pregnant and breast-feeding women on vegan diets and their infants.... If dietary changes are not acceptable to parents, vitamin B12 supplements are essential."

Grattan-Smith et al.36 (1997, Australia) reported the cases of 3 infants of vegan mothers.

Infant 1: sB12 of 47 pg/ml; intermittent tremors developed at 4 months; mother's sB12: 203 pg/ml. At 10 months, he was treated with injections of 1000 mcg B12/day for 6 days and developed tremors which lasted for 6 weeks. By 23 months, his motor skills were normal, but his intellectual development appeared to be a bit slow for his age.

Infant 2: At 12 months, she became pale, irritable, lethargic, and constipated; sB12 of 50 pg/ml. After the second 1500 g B12 injection, she developed tremors which eventually went away and she returned to normal

Infant 3: Stopped developing after 1 year; developed twitching at 18 months along with other neurological problems; sB12 of 115 pg/ml; increased urinary MMA; brain atrophy. Mother's diet showed a B12 intake of 0.3 mcg/day and sB12 of 202 pg/ml. She also had B12 malabsorption thought to be due to a temporary small intestine problem caused by B12 deficiency. After injections of 500 mcg B12/day, the child's twitching developed into episodes more like seizures as his neurological status gradually improved. No further follow-up was noted.

Grattan-Smith et al.36 noted that other such infants have also developed tremors and suggests that the tremors following injections may be a result of giving so much B12 that some parts of the body develop a temporary metabolic imbalance. They state that in the cases of nutritional deficiency, it seems unnecessary to give such high doses of B12.

Goraya33 (1998, India) reported that in India, many infants have "infantile tremor syndrome", similar to the case described by von Schenck103 (1997; above). This occurs in exclusively breast-fed infants from low socioeconomic conditions. Documented B12 deficiency, megaloblastic anemia, and response to B12 therapy has been observed in some but not all patients.

Renault et al.81 (1999, France) reported 2 strictly breast-fed infants of vegan mothers. After normal development, psychomotor regression appeared after the 6th month, leading to severe lack of muscle tone, sensory nerve disease, apathy, blood problems, and weight loss before the 12th month. Their serum B12 was undetectable. They were given B12 and the symptoms cleared up. One mother had a sB12 of 109 pg/ml, macrocytosis, and a normal Schilling test.

Wiley et al.105 (1999, Australia) reported the results of using a new method to screen newborns for inborn error of metabolism. In examining 137,120 babies, they found 2 B12-deficient babies of vegan mothers. There was no more information on these babies given. "B12-deficient" was not defined.

The studies with an asterisk were studies reported between 1981 and 2000 in which infants of vegan mothers have suffered from B12 deficiency. In all cases, the infants are healthy until about 6-12 months of age after which they fail to thrive and show developmental regression.

They are lethargic and lose their ability to use their muscles adequately and sometimes cannot sense properly. They normally have macrocytic anemia. For these studies, I will only list unusual circumstances surrounding the case. Unless otherwise noted, these infants were exclusively breast-fed by mothers who did not take supplements.

Vegan Infants Taking B12 Supplements

Sanders86 (1988, UK) studied the growth and development of 37 vegan children. All were breast-fed for their first 6 months and in most cases well into their second year.

The majority of children grew and developed normally but they tended to be smaller in stature and lighter in weight than the general population. Energy, calcium, and vitamin D intakes were usually below the recommended amounts. Their diets were generally adequate with a few children having low intakes of riboflavin and B12.

Most parents knew to supplement the diet with B12. Sanders concluded that provided sufficient care is taken, a vegan diet can support normal growth and development.

B12 & Breast Cancer

Recently, there has been some research concerning a link between low B12 status and cancer. It is thought that since B12 is needed for proper DNA production, a lack of B12 could have an effect on cancer by changing DNA such that the cell becomes cancerous.

Wu et al.107 (1999, USA) investigated the incidence of breast cancer with serum folate, B12, and B6 in two separate groups of women. It was the first study to look at B12 and breast cancer. There was no association between serum folate or B6.

There was a small increased risk for the postmenopausal women in the lower one-fifth of B12 levels (averaging 280 pg/ml) in one of two groups. In the other group, where lower levels of B12 were not associated with increased risk, the women in the lowest one-fifth of sB12 levels averaged 312 pg/ml.

In reviewing the literature on B12 and cancer, Choi16 (1999, USA) points out that although early links between breast cancer and per capita animal fat consumption were seen, prospective studies looking at the association between a woman's daily total fat intake and breast cancer risk did not show a clear association. (Alcohol is a well-established risk factor for breast cancer.)

Most case-control studies have suggested a higher intake of fiber, vegetables, and fruit is protective. The fiber is thought to reduce estrogen levels. Despite this, vegetarians have not been shown to have lower mortality rates from breast cancer than NV with similar lifestyles.54 Could this be because of reduced B12 status?


How Can a Diet That is the Most Natural Diet Require Supplements?

Whether a majority of prehistoric humans were vegans for a significant period of evolutionary history cannot be determined from this review. What does appear to be true is that the longer someone is vegan (and not supplementing with B12), the lower their B12 levels will drop. It is unlikely that vegans can achieve optimal health without supplementing their diet with B12.

In Western society today, it is easy to ensure high B12 intakes while still eating a diet that is in accordance with our ethical values, regardless of how our human ancestors ate. In fact, vegetarians who supplement with B12 can possibly have superior B12 status to nonvegetarians. I would encourage vegan advocates to make achieving superior B12 status for all vegans one of our goals.

Encourage New Vegans to Concern Themselves with B12 Supplements

As pointed out earlier (see Transport in the Blood), B12-TC2 levels fall below normal within days after absorption stops, resulting in the tissues not receiving adequate B12. B12 intake is not normally necessary for B12 absorption (see Enterohepatic Circulation) because the body can adjust to the lower intakes by reabsorbing B12 that normally would have been excreted.

But these reabsorption mechanisms may take time to adjust to a sudden drop in B12 intake. Also, these mechanisms will not keep a vegan, who is not supplementing, in B12 balance (where one is taking in as much B12 as they are losing). Some people who try a vegan diet may already be starting off with low B12 levels or hampered absorption mechanisms.

All or some of these factors above may be enough for a new vegan to notice a negative difference in how they feel and go back to eating animal products. Therefore, it is prudent for vegans to eat B12 on a regular basis (at least daily) immediately after starting a vegan diet. This will keep them in positive B12 balance, keeping their B12-TC2 at normal levels and providing their tissues with adequate B12.

Vegan Outreach

[ Page 1 | Page 2 | References ]

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