VITAMIN B-12

Should You Worry?
by
Charles R. Attwood, M.D., F.A.A.P.

sabella, my granddaughter, is now a year old. She has never tasted meat or milk. Still breastfed, her physical growth and development, according to the Denver Developmental Scale, is well above average. She has the smoothest skin I've ever seen -- none of the rough areas of eczema usually seen in infants. Isabella also doesn't have ear infections, wheezing, or other respiratory illness seen so often in milk drinkers. Where, her regular pediatrician asks, does she get vitamin B-12. He points out correctly that it's only found in animal products. The answer, for now, is from breastmilk. Her mother recently asks me whether or not a supplement will be necessary as she get older.

So let's look at some older vegetarians to see how they deal with the B-12 dilemma.

Ocean Robbins, of Santa Cruz, California, the 22 year old son of EarthSave founder John Robbins, has never eaten meat -- and for the past 10 years he has consumed no animal products whatsoever. Yet, his physical growth has always been above average and he's rarely been sick. Ocean excelled in both sports and academics throughout his childhood, setting elementary school records for pull-ups, pushups, and the 10 Km run for age 10. He and his father, another famed vegetarian, together recently ran a full marathon. Both take B-12 supplements daily, which Ocean reminds me, doesn't come from animal sources.

Dick Gregory, the great stand-up comic and civil rights leader, has been a vegetarian since 1964. His physical endurance, which has been proven by several ultra-long distance walks, has not diminished during the past three decades. At age 64, he remains extremely physically active and hasn't been ill in many years. When I asked if he took supplements containing B-12, he said, "Oh yes, quite a few."

Isabella's Recommended Daily Allowance (RDA) for this vitamin, known to be necessary for cell division and blood formation, is estimated by the National Research Council to be 1 microgram (0.001 mg). The RDA for Ocean and Dick should be about 2 micrograms (0.002 mg). Millions of people worldwide, however, have no known source for this amount of B-12, yet they remain perfectly healthy. So where is it coming from? Are there any plant sources?

Readers of Frances Moore Lappe's Diet For A Small Planet may remember reading in its first edition (1971) that certain fermented soy products, such as tempeh, miso, and seaweed contained vitamin B-12. These sources have recently been shown to contain only the inactive analogue of the vitamin, not metabolized by humans. Ironically, they may actually interfere with the metabolism of active B12.

The American Academy of Pediatrics' Committee on Nutrition states that deficiencies of vitamin B-12 -- known chemically as cobalomin -- although extremely serious, and which ultimately may lead to irreversible nerve damage, are rarely found among vegetarian children or adults throughout the world. The rural Chinese for example, some of which consume only vegetables, fruits, and gains, show no symptoms attributable to deficiencies of this vitamin. So the risk is not great. Personally, during 35 years of pediatric practice, I've never encountered a single case of B-12 deficiency. Yet, most of my colleagues who advocate a plant-based diet are somewhat cautious and recommend some source of B-12. Dr. Dean Ornish suggests an occasional cup of skim milk. Dr. Neal Barnard recommends taking a multivitamin or B-12 fortified foods.

The most likely explanation for this extreme rarity of B-12 deficiencies among vegans is self-synthesis. Since bacteria from the soil on plants consumed by animals produce B12 within their gastrointestinal tracts, it's reasonable to assume that the same may happen when individuals eat natural foods? This is more likely if the plants are not carefully cleaned, washed, or overcooked. The Vegetarian Resource Group states that some vegans may get B-12 from inadequate hand washing, but they are quick to point out that this isn't a reliable source. Also, it's been suggested that B-12, like iron, may be absorbed more efficiently by vegans than by people consuming animal products.

Furthermore, a little of this vitamin goes a long, long way. The body can store it for at least 5 years, maybe longer, so there's virtually always adequate amounts for anyone who occasionally eats meat or dairy products. In fact, there's evidence that vegans who previously ate animal-based food may have vitamin B-12 stores that will not be depleted for 20 to 30 years or more.

A very interesting report from Europe has concluded that plants may contain B-12, especially green vegetables, if fertilized organically. More on this later.

So in summary, it seems that vegetarians who consume enough calories face very little chance of developing a B-12 deficiency. But let's face it, parents would like total assurance that they and their children will not be at risk. For them I would suggest a multivitamin containing B12, a fortified breakfast cereal, fortified soy milk, or fortified meat substitutes. Some forms of nutritional yeast contain adequate amounts of B-12. These non-animal sources are fine; just read the labels. Then you can go ahead and wash your hands.

References:

(1) Herbert V: Vitamin B12: Plant sources, requirements, and assay. Am J Clin Nutr 48: 852-858, 1988

(2) Albert MJ, et al: Vitamin B12 synthesis by human small intestinal bacteria. Nature 283: 781-782, 1980

(3) Herbert VD and Colman N: Folic acid and vitamin B12. Modern Nutrition in Health and Disease, 7th ed. Philadelphis: Lea and Febiger, 1988; 388-416

(4) Immerman AM: Vitamin B12 status on a vegetarian diet. A critical review. WLD Rev Nutr KIet 37: 38-54, 1981

(5) Ornish, Dean: Dr. Dean Ornish's Program for Reversing Heart Disease. Random House, 1990

(6) Barnard, Neal: Eat Right Live Longer. Harmony Books, 1995

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