Description
Why the number is 1000 mcg when you only need 2.4
The recommended daily amount of vitamin B12 for adults is 2.4 mcg. This tablet contains 1000 mcg — more than 400 times that. It is not a misprint, and it is the most misread number on the B12 shelf.
Here is the reason. B12 from food and from small doses is absorbed using a carrier protein made in the stomach, and that pathway is saturable: it can only move a limited amount at a time. Anything beyond that is absorbed passively, and only a small fraction gets through. High-dose oral B12 works by deliberately overshooting the carrier so that the small passive share still adds up to a useful amount. That is why the number on the bottle looks extreme and is not.
Who that matters for
- Adults over 50. The NIH notes that a meaningful share absorb less of the B12 that is bound to food, and advises getting B12 from fortified foods or a supplement.
- People on long-term acid-reducing medication, since stomach acid is what releases B12 from food in the first place.
- Vegetarians and vegans. B12 occurs naturally almost only in animal foods.
What time release does — and does not do
Time release spreads the tablet's dissolution out instead of delivering everything at once. It changes the pace, not the total. Swallow it whole: splitting or crushing a time-release tablet defeats the coating that makes it time release. B12 is water-soluble and has no established upper limit — what the body does not use is excreted rather than stored.
The math on this bottle
75 tablets, one a day — 75 days. At $10.99 that is about 15 cents a day.
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These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. Talk to your healthcare provider or pharmacist before starting a supplement, especially if you take prescription medication.