food sources from which to obtain it, and it's a large molecule, difficult to absorb. I hope she is using the sublingual kind.
I did get the 5000mcg for our daughter, and she took it every day for several months. On her last doctor visit (I went with her), the NP asked if she was taking B12. She said yes, and the NP said she thought so, since her B12 level was too high to read. lol But the NP said her iron was low, so our daughter eats liver once a week now.
Some B12 is stored in our livers with the excess urinated away. And it's said that you can't overdose on B12. However, it occurred to me that B12 has a cobalt attached to it, and I wondered if that could be a problem. I dug around and found the "mineral wheel", which shows that iron and cobalt work against each other, so then I wondered if the large amount of cobalt caused the iron deficiency. And then I read that B12 deficiency masks an iron deficiency, so now that her B12 is in order, maybe the iron deficiency is just showing up. Nutrition is a very hard thing!
The NP told her she could stop taking the B12, but since our daughter takes Metformin, which depletes B12, I'm not sure what to think. I told her to stop taking it for a while, but I'm not comfortable with her never taking it again. Although if she continues to eat liver every week or two, she will get the B12 along with the iron anyway (if she can absorb the B12). So, I wait.
One of our friends who had her stomach removed some years ago because of a cancer gives herself a 1000mcg injection once a month, so I guess that's adequate for someone who doesn't have a deficiency. I don't know why she doesn't just use the little sublingual instead of an injection.
B12 is cheap. It's easy to supplement. My advice to anyone wanting to supplement is use a sublingual and be sure to get methylcobolamin, not cyanocobolamin, which is what most ordinary products contain. The methylcobolamin is already bioavailable, which is great. Some people don't have the gene that converts the other forms, so the body can't absorb and use it.
I order the Superior Source No Shot Methylcobolamin from Amazon. Right now, we have the 5000mcg, which I have started splitting, and we're only taking it once a month. When we use it all, I'll order a lower dose.