Vitamin b-12

Human and Clinical Nutrition

Vitamin B-12 Status of Long-Term Adherents of a Strict uncooked Vegan Diet ("Living Food Diet") Is Compromised1'2
ANNA-LIISA
Departments

RAUMA? RUTTA TÖRRÖNEN,* OSMO HÄNNIHEN*
of Clinical Nutrition and *Physiology, University of Kuopio, FIN-70211, Kuopio, Finland

AND HANNÜMYKKÄNEN

ABSTRACT The present study examined the vitamin B-12 status inlong-term adherents of a strict uncooked vegan diet called the "living food diet." The study was comprised of two parts. In the cross-sectional part, the data on serum vitamin B-12 concentrations and dietary intakes in 21 (1 male, 20 females) long-term adherents (mean 5.2 y, range 0.7-14) of the "living food diet" were compared with those of 21 omnivorous controls matched for sex, age, social statusand residence. In the longitudinal part of the study, food consumption data were collected and blood samples were taken from nine "living food eaters" (1 male, 8 females) on two occasions 2 y apart. The cross-sectional study revealed significantly (P < 0.001, paired t test) lower serum vitamin B-12 concentrations in the vegans (mean 193 pmol/L, range 35-408) compared with their matched omnivorouscontrols (311, 131-482). In the vegan group, total vitamin B-12 intake correlated significantly (r = 0.63, P < 0.01) with serum vitamin B-12 concen tration. The vegans consuming Nori and/or Chlorella seaweeds (n = 16) had serum vitamin B-12 concentra tions twice as high as those not using these seaweeds (n = 5) (mean 221 pmol/L, range 75-408, vs. 105, 35-252, P = 0.025). In the longitudinal study,six of nine vegans showed slow, but consistent deterioration of vitamin B-12 status over a 2-y observation period. On the basis of these results we conclude that some seaweeds consumed in large amounts can supply ad equate amounts of bioavailable vitamin B-12. However, the average use of seaweeds and fermented foods by "living food eaters" will not supply enough vitamin B12 to maintain the bodyvitamin B-12 status. J. Mutr. 125:2511-2515, 1995. INDEXING KEY WORDS:

These food preparation methods are thought to en hance the growth of vitamin B-12-producing bacteria (Ro et al. 1979, Van Veen and Steinkraus 1970), and therefore the advocates of the "living food diet" are convinced that their diet will supply more vitamin B12 than an ordinary vegan diet. Furthermore, the ad vocates believethat this diet, which is rich in lactobacilli, will modify the microflora at the distal ileum, thereby enhancing the amount of bioavailable vitamin B-12. In fact, only minute amounts of vitamin B-12 are found in fermented foods (Österdahl and Johans son 1989), and most of vitamin B-12 in seaweeds are analogues of the true vitamin (Herbert and Drivas 1982, van den Berg et al. 1988). Therefore, itremains to be shown whether the long-term use of large amounts of uncooked fermented foods and seaweeds could actually supply enough biologically active vi tamin B-12.

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SUBJECTS AND METHODS Subjects. The present study is comprised of two parts. In the cross-sectional part, 21 (1 male, 20 fe males) long-term adherents of a strict uncookedvegan diet ("living food diet") were recruited via an adver tisement in a living food eaters' newsletter in Finland ('The Friend of Living Food'). In the longitudinal study, the subjects were nine "pioneers" who had partici pated in our earlier study two years before (Rauma et al. 1994). The average duration of the vegan diet in
1 Supported by the Wihuri Foundation tural Foundation. 2 The costs ofpublication and by the Finnish Cul

• uegan • u¡taminB-12 • raw food • fermented food • seaweed

humans

of this article were defrayed in part

Strict vegans, called "living food eaters," consume all of their food uncooked, and most of the daily food items are fermented or sprouted (Rauma et al. 1993).

by the payment of page charges. This article must therefore be hereby...