Vitamin B12 is a complicated vitamin with a unique absorption mechanism and a number of inactive analogues (molecules that appear to be active B12, but actually are not) that possibly interfere with its function. Vitamin B12 is generally found in all animal foods (except honey). Contrary to the many rumors, there are no reliable, unfortified plant sources of vitamin B12, including tempeh, seaweeds, and organic produce. One of the earliest studies conducted on vegans, from the U.K. in 1955, described significant vitamin B12 deficiency in the vegans with some suffering from nerve damage and dementia. This, as well as many case studies since then of vitamin B12 deficiency in vegans, and a great deal of other evidence detailed here, has led to the overwhelming consensus in the mainstream nutrition community, as well as among vegan health professionals, that vitamin B12 fortified foods or supplements are necessary for the optimal health of vegans, and even vegetarians in many cases. Luckily, vitamin B12 is made by bacteria such that it does not need to be obtained from animal products.
Despite the overwhelming evidence that vegans without a reliable source of vitamin B12 are likely harming their health, some vegan advocates still believe that "plant foods provide all the nutrients necessary for optimal health," and do not address vitamin B12 when promoting the vegan diet. Other advocates acknowledge the need for B12, but only as an afterthought. And still others emphasize that humans need only small amounts of B12 and that it can be stored in the body for years.
Recommended dietary amounts (RDAs) are 2.4 micrograms daily for ages 14 years and older, 2.6 micrograms daily for pregnant females, and 2.8 micrograms daily for breastfeeding females. Those over 50 years of age should meet the RDA by eating foods reinforced with B12 or by taking a vitamin B12 supplement. Supplementation of 25-100 micrograms daily has been used to maintain vitamin B12 levels in older people. A doctor and a pharmacist should be consulted for use in other indications.
For vitamin B12 deficiency, 125-2,000 micrograms of cyanocobalamin has been taken by mouth daily for up to 2.5 years or longer. Five hundred micrograms of sublingual (under the tongue) vitamin B12 has been used daily for up to four weeks.
Appreciate that, Dr J. Im vegetarian and have been taking vit B12 supplements until recently when a blood test end of Nov showed up levels over the maximum (@ least according to Hanley Moir) of 765. Also have lowish ferritin of 66 for which is take supplementation, but no docs have ever really remarked on either very much, apart from you might want to think about tabs.
So, all the spinach obviously isn't helping lol
GT1a since 1988, diagnosed 1990
F0, tx naive
VL 262,000 ALT 40 AST 26 GGT 13 Fibroscan 04/12/15 - 2.9
Started Mesochem sof/dac 12 weeks 01/01/2016
11/02/2016 - 6 weeks UNDETECTED