hydroxide ligand is displaced by the toxic cyanide ion, and the resulting non-toxic cyanocobalamin is excreted in urine. Dietary recommendations Most people in the United States and the United Kingdom consume sufficient vitamin B12. However, proportions of people with low or marginal levels of vitamin B12 reach up to 40% in the Western world. Grain-based foods can be fortified by having the vitamin added to them. Vitamin B12 supplements are available as single or multivitamin tablets. Pharmaceutical preparations of vitamin B12 may be given by intramuscular injection. Since there are few non-animal sources of the vitamin, vegans are advised to consume a dietary supplement or fortified foods for B12 intake, or risk serious health consequences. Children in some regions of developing countries are at particular risk due to increased requirements during growth coupled with diets low in animal-sourced foods. The US National Academy of Medicine updated estimated average requirements (EARs) and recommended dietary allowances (RDAs) for vitamin B in 1998. The EAR for vitamin B for women and men ages 14 and up is 2.0μg/day; the RDA is 2.4μg/day. RDA is higher than EAR so as to identify amounts that will cover people with higher than average requirements. RDA for pregnancy equals 2.6μg/day. RDA for lactation equals 2.8 μg/day. For infants up to 12 months the adequate intake (AI) is 0.4–0.5μg/day. (AIs are established when there is insufficient information to determine EARs and RDAs.) For children ages 1–13 years the RDA increases with age from 0.9 to 1.8μg/day. Because 10 to 30 percent of older people may be unable to effectively absorb vitamin B naturally occurring in foods, it is advisable for those older than 50 years to meet their RDA mainly by consuming foods fortified with vitamin B or a supplement containing vitamin B. As for safety, tolerable upper intake levels (known as ULs) are set for vitamins and minerals when evidence is sufficient. In the case of vitamin B there is no UL, as there is no human data for adverse effects from high doses. Collectively the EARs, RDAs, AIs and ULs are referred to as dietary reference intakes (DRIs). The European Food Safety Authority (EFSA) refers to the collective set of information as "dietary reference values", with population reference intake (PRI) instead of RDA, and average requirement instead of EAR. AI and UL are defined by EFSA the same as in the United States. For women and