It was Christmas week 1990 in Oakland. Steven Bloom was wandering through The Lot, that timeless gathering of hippies that springs up in the parking lot before every Grateful Dead concert, when a Deadhead handed him a yellow flyer.
Because of the general safety of the vitamin, upper limits for normal intake do not exist. If your blood values for the vitamin fall below a range of 170 to 250 picograms per milliliter, you may develop a B12 deficiency.
5. Get help from a doctor now âº. Low Vit B12.: Low vit B12 (vit B12 deficiency) usually at levels below 200, and reportedly at levels below 400 may lead to permanent neurological damage. It is easily treated with once monthly injections or by over the counter supplementation with the subligunal form being preferred.