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If vitamin B12 is found to be low, then further testing for intrinsic factor antibodies, antiparietal antibodies, methylmalonic acid and homocysteine

Those with diseases that affect the gut, such as Crohns disease or celiac disease, are also at risk ( Summary Those at greatest risk of vitamin B12 deficiency are vegans and vegetarians, who get little to no B12 from the diet

solution applications can be filtered if endotoxin removal is required

Whilst the intrinsic factor-mediated absorption pathway can only process approximately 1.52 micrograms of B12 at a time, passive diffusion allows absorption of about 1% of higher doses