B12 Deficiency

Vitamin B12 is one that needs to be consumed regularly because the body is only able to absorb a very small amount of it at a time--even if it is depleted. It's not like you can catch up by taking one big dose one day. Yogurt might be a good source, eggs have it; but if you're taking supplements, be aware that the usual form found in supplements, cyanocobalamin, is virtually useless and not worth the money. Within 48 hours of taking it, 98% will have exited your body via your urine, according to at least one study. Hydroxocobalamin is a slightly better choice, but the best one, and becoming more widely available these days, is methylcobalamin. It's worth the extra money to get it.

If you're eating foods high in folate, e.g. lots of green leafy vegetables, you may not know that you're deficient in B12. Deficiency is dangerous. If you don't like greens so much, you're more likely to notice when your B12 levels drop to dangerous levels. Symptoms of B12 deficiency include pernicious anemia, loss of memory, reduced sense of taste and smell, numbness or tingling in hands or feet, fatigue, depression, perhaps even hearing loss. Prolonged deficiency can cause permanent brain damage or even death. As people age and produce less intrinsic factor in the stomach by which to absorb B12, even regular meat eaters can become deficient. But for most people, eating something with B12 several times a week should be adequate to maintain normal levels. If you are treating a deficiency, you'll want to have a good source of it daily.

 

But the dosage is so absurdly high that 98% is enough?