flolalapine
Massacre des légumes
Posotion de l'ADA 2009, les références 46 47 et 48 traitent de la B12 (non je ne traduis pas):
Metabolic vitamin B12 status on a mostly raw vegan diet with follow-up using tablets, nutritional yeast, or probiotic supplements.
Donaldson MS.
Hallelujah Acres Foundation, Shelby, N.C., USA. [email protected]
Abstract
BACKGROUND: Pure vegetarian diets might cause cobalamin deficiency due to lack of dietary intake. It was hypothesized that a population following a vegan diet consuming mostly raw fruits and vegetables, carrot juice, and dehydrated barley grass juice would be able to avoid vitamin B12 deficiency naturally.
METHODS: Subjects were recruited at a health ministers' reunion based on adherence to the Hallelujah diet for at least 2 years. Serum cobalamin and urinary methylmalonic acid (MMA) assays were performed. Follow-up with sublingual tablets, nutritional yeast, or probiotic supplements was carried out on subjects with abnormal MMA results.
RESULTS: 49 subjects were tested. Most subjects (10th to 90th percentile) had followed this diet 23-49 months. 6 subjects had serum B12 concentrations <147 pmol/l (200 pg/ml). 37 subjects (76%) had serum B12 concentrations <221 pmol/l (300 pg/ml). 23 subjects (47%) had abnormal urinary MMA concentrations above or equal to 4.0 microg/mg creatinine. Sublingual cyanocobalamin and nutritional yeast, but not probiotic supplements, significantly reduced group mean MMA concentrations (tablet p < 0.01; yeast p < 0.05, probiotic > 0.20).
CONCLUSIONS: The urinary MMA assay is effective for identifying early metabolic cobalamin deficiency. People following the Hallelujah diet and other raw-food vegetarian diets should regularly monitor their urinary MMA levels, consume a sublingual cobalamin supplement, or consume cobalamin in their food.
Total homocysteine, vitamin B(12), and total antioxidant status in vegetarians.
Herrmann W, Schorr H, Purschwitz K, Rassoul F, Richter V.
Department of Clinical Chemistry/Central Laboratory, University Hospital of the Saarland, D-66421 Homburg/Saar, Germany. [email protected]
Abstract
BACKGROUND: Decreasing or eliminating animal products from the diet decreases the intake of some essential nutrients, such as vitamin B(12), which may lead to hyperhomocysteinemia. We investigated vitamin B(12)-dependent metabolism and oxidative stress in groups with various or no intake of meat or animal products.
METHODS: We investigated 44 high meat eaters, 19 low meat eaters, 34 lacto-ovo/lacto vegetarians, and 7 vegan vegetarians. Homocysteine (HCY) was assayed by HPLC, methylmalonic acid (MMA) by capillary gas chromatography-mass spectrometry, serum folate and vitamin B(12) with a chemiluminescence immunoassay, and total antioxidant status (TAS) by a Randox method.
RESULTS: The mean serum HCY concentration of vegetarians was significantly increased, and in vegans the median concentration exceeded 15 micromol/L. Vegetarians had a higher serum concentration of MMA but a lower TAS. Vitamin B(12) and folate did not differ significantly between vegetarian and omnivorous subjects. Overall, HCY and MMA were significantly correlated. Vitamin B(12) correlated negatively with MMA, HCY, and folate, whereas the correlation with TAS was positive. Backward regression analysis revealed an independent influence of MMA on HCY, of HCY and vitamin B(12) on MMA, and of vitamin B(12) on TAS. The increased MMA concentration suggested a 25% frequency of functional vitamin B(12) deficiency in all vegetarians. Serum vitamin B(12) was below the lower reference limit in only five subjects.
CONCLUSIONS: Functional vitamin B(12) deficiency in vegetarians may contribute to hyperhomocysteinemia and decreased TAS, which may partly counteract the beneficial lifestyle of vegetarians. However, increased serum HCY is most likely not responsible for the lower TAS values in vegetarians. We recommend assaying of MMA and HCY to investigate functional vitamin B(12) status.
Je rappelle que cette position de l'ADA est très favorable au végétarisme à tous les âges de la vie. La traduction est disponible sur le site de l'APSARES. Donc oui, il y a un consensus scientifique, avec des études à l'appui, pour recommander cette supplémentation en B12. Il y a des tas d'études sur Medline qui montrent à quel point le régime végétarien est bon pour la santé globalement.Vegetarian lifestyle and monitoring of vitamin B-12 status.
Herrmann W, Geisel J.
Department of Clinical Chemistry-Central Laboratory, University Hospital of the Saarland, Bld. 40, D-66421 Homburg/Saar, Germany. [email protected]
Abstract
Vegetarians are at risk to develop deficiencies of some essential nutrients, especially vitamin B-12 (cobalamin). Cobalamin occurs in substantial amounts only in foods derived from animals and is essential for one-carbon metabolism and cell division. Low nutritional intake of vitamin B-12 may lead to negative balance and, finally, to functional deficiency when tissue stores of vitamin B-12 are depleted. Early diagnosis of vitamin B-12 deficiency seems to be useful because irreversible neurological damages may be prevented by cobalamin substitution. The search for a specific and sensitive test to diagnose vitamin B-12 deficiency is ongoing. Serum vitamin B-12 measurement is a widely applied standard method. However, the test has poor predictive value. Optimal monitoring of cobalamin status in vegetarians should include the measurement of homocysteine (HCY), methylmalonic acid (MMA), and holotranscobalamin II. Vitamin B-12 deficiency can be divided into four stages. In stages I and II, indicated by a low plasma level of holotranscobalamin II, the plasma and cell stores become depleted. Stage III is characterized by increased levels of HCY and MMA in addition to lowered holotranscobalamin II. In stage IV, clinical signs become recognizable like macroovalocytosis, elevated MCV of erythrocytes or lowered haemoglobin. In our investigations, we have found stage III of vitamin B-12 deficiency in over 60% of vegetarians, thus underlining the importance of cobalamin monitoring in this dietary group.
. La B12 étant issue d'une bactérie: ne pas se laver les mains après être aller aux toilettes, ne pas laver les fruits, vivre au contact d'animaux, etc. favorisera l'absorption de B12. Cela ayant quelques inconvénients, il me semble qu'il reste préférable de prendre des suppléments 
