Stuff to Know About B12

I posted this on the RNY board the other day but thought I'd put it here too in case it helps anyone.  

After RNY, we need to take a B12 supplement. Since part of our small intestine has been bypassed we won’t absorb B12 as well as we used to, but even more concerning is the fact that we need something called intrinsic factor in order to absorb B12 and we have very little of that in our new pouch. Therefore we will absorb very little B12 that we swallow. That includes B12 in food we eat and B12 in a multivitamin. Doesn’t matter if it’s a multi that we swallow whole or a chewable or a liquid. If we swallow it, we won’t absorb much of the B12 in it.

So we need a B12 supplement that we don’t swallow, and there are several to choose from. There are sublinguals that dissolve under the tongue, there is a patch you stick behind your ear, there is a nasal spray, and there are injections. Most people will absorb any of these equally well so it’s just a matter of personal preference. Sublinguals and injections are cheap. The nice thing about injections is most people only need them once a month. The nasal spray is just once a week but you need a prescription for it and depending on your insurance coverage it might be costly. The patch is convenient and most people just need one a week, but it’s kind of costly.

If you use a sublingual, the ASMBS recommends 350-500 mcg per day. If you use injections, they recommend 1000 mcg once a month. The ASMBS doesn’t address the patch or nasal spray, but the patch contains 1000 mcg and is normally used once a week, while the nasal spray contains 500 mcg and is normally used once a week. The reason the doses seem very different is because the B12 is absorbed differently depending on how you take it.

B12 is supposed to be pretty rare in the general population, but I kind of question that. Many people go their entire life without ever getting their B12 tested, so how would they know if they were deficient? Also, many labs and health care professionals use ridiculously low values as a “normal range," which I’ll talk about in just a moment. Regardless, it’s not rare in RNY folks.

Most labs and health care professionals consider anything from 211-911 to be “normal" for B12. This confuses me greatly. Studies show that when B12 drops below 550, people start experiencing things like depression, fatigue, difficulty concentrating, and problems with short-term memory. When it drops below 400, they start having numbness and tingling in the hands and feet. That’s because they are developing nerve damage. And that nerve damage is often permanent. Never goes away. They can start taking more B12 and get their level up and prevent further damage, but they will probably feel like their hands and feet are falling asleep for the rest of their lives. So I don’t get how labs can say that’s normal.

It’s also not bad for your B12 to be over 911. There is some question about whether or not there is such a thing as B12 toxicity. Some sources say yes, some say no. If there is, it would only occur when your B12 is very high, probably over 2000. And it’s probably not very dangerous if your B12 does get over 2000. It will not cause permanent nerve damage or anything like that. Still, if your B12 is close to 2000, it probably makes sense to cut back on your supplement. I would suggest cutting back slowly, though, and watching your labs carefully because you really don’t want to get too low.

When you get labs done, it’s important to make sure you get the actual number. Don’t take your doc’s word for it that it’s OK. Docs often tell people their B12 is normal when it’s 300 or lower, when they could be developing permanent nerve damage.

VSG and DS people MAY need a b12 supplement too but lap banders usually do not.

Kelly

Agree and VSG and DSrs probably will do better with sublinguals or shots as well.

--gina

Yeah, they would because with the smaller stomach, they also have less intrinsic factor.

I'm taking 3000mcg sublingual of cyano B12 once a day for right now.  My labs won't be until the first of May.  Is there a fat storage/release issue with B12 that would make my numbers be skewed this first set of labs?

Nah, it's not a fat soluble vitamin, it's water soluble.

You may be taking more than you need but don't worry about it right now.  If your number is really high on your labs you can cut back a bit but what you're taking now will not hurt you.  There's just no sense taking more than you  need forever 'cause you'll save money, you know?

Thanks for the info Kelly.

I bought the BA sublingual B12 and it took forever for them to dissolve so I went back to the ones I got at Sam's and they dissolve very fast.  I use one per day 2500mcg.  I think the BA ones were less than that.  My labs have always been good - over 1100.  1700 last time.

Do you think there is a difference in the absorption in the fast dissolving vs the slow ones?

Linda

Excellent labs.  Don't let your doc tell you that's too high, either.

I would not think there is a difference in the ones that dissolve fast or slow, but I don't really know that.  Obviously what you're using is working fine for you, though.

Kelly

Hey Kelly,   I just got my labs back today, and put everything on the sheet you sent me!  My B12 was 1998 and I take the Sam's Club version of sublingual 2500 mgs everyday.  How much should I cut back?  I am seeing my Dr on Monday.  Your sheet had alot of stuff that they didnt test for, so I am going to ask her about that.   I will let you know what she says....                          Joan

I'd probably go to doing the 2500 mcg every other day or every three days.  Your doc will probably tell you it's too high and to cut way back.  But your B12 can fall super super fast and yours is not dangerously high or anything.  I would cut back but I wouldn't do anything drastic, personally.

I take a liquid B Complex that also has 1200mcg of B12 in it.  I hold it in my mouth for a minute or so before swallowing.  I noticed my B12 numbers skyrocket once I started taking it, as I was also taking a sublingual.  I cut my sublingual to 500mcg a day with the B12 from the complex making up the rest.  My labs just indicated >1500.