Ann,

The supplemental amounts in the rows of this chart were devised to provide approximately the same amounts of absorbed B12.

> I also read that high B12 supplementation can cause acne because skin bacteria stop producing B12 and start producing more porphyrins. If that’s true, I wonder how it can be distinguished from cobalt sensitivity.

That appears to be true (according to this study) but it probably applies mostly to people receiving injections. Someone who receives a vitamin B12 injection of 1,000 µg will effectively “absorb” all 1,000 µg while someone taking a 1,000 µg oral supplement will only absorb about 1%. Only 1 out of 10 healthy subjects receiving an injection developed signs of acne.

I’ve been reading a lot about folate and folic acid the past few days and found out something that had slipped past my attention previously—that food folate can’t mask a B12 deficiency, only supplemental folic acid, 5-MTHF-glucosamine, and L-5-MTHF-Ca can mask B12 deficiency. It’s kind of the key point of the methylfolate trap, and I’m a little embarrassed to say that I never realized it. I’ve updated the section of the site about folic acid masking B12 deficiency.

Thanks. The kidney question is regarding someone else, good to know that the risk doesn’t seem so much.

I wonder if 3x 3mcg per day is similar to 1x 100mcg, in terms of what is absorbed. If a lower supplement amount can have the same impact and possibly less chance of skin imbalances, maybe that’s preferable.

I also read that high B12 supplementation can cause acne because skin bacteria stop producing B12 and start producing more porphyrins. If that’s true, I wonder how it can be distinguished from cobalt sensitivity.

Ann,

> Also it wasn’t being taken for a while as my child stopped liking it and we tried a few brands before finding another one, which is now 3mcg per tablet, 3 times a day (as the packet says 2-3 per day, but I’m separating the times).

That’s plenty of B12 for a child or an adult.

Folate can’t mask the neurological problems caused by B12 deficiency; it can only mask the red blood cell symptoms.

Your doctor’s advice sounds reasonable.

> Also, I read that sublingual B12 isn’t necessarily better than normal tablets, and intrinsic factor does most of the absorption. Do you know if that recommendation has changed?

No, you don’t need sublingual.

The amount of cyanide is physiologically insignificant and the precautions for people with kidney disease are just to be extra careful, not because of any cases of definite kidney damage. But there’s methylcobalamin instead of cyanocobalamin; I’d recommend talking to your doctor about it.

How about someone who has previously had congenital kidney issues but has had that corrected, or else, someone with risk factors but no diagnosis? Would they need to be wary about possibly not clearing the cyanide?

Also, I read that sublingual B12 isn’t necessarily better than normal tablets, and intrinsic factor does most of the absorption. Do you know if that recommendation has changed?

Thanks, not specifically B12 deficiency symptoms, but the multivitamin we were using turns out to have too low B12 (I originally checked it for a younger age bracket). Also it wasn’t being taken for a while as my child stopped liking it and we tried a few brands before finding another one, which is now 3mcg per tablet, 3 times a day (as the packet says 2-3 per day, but I’m separating the times).

Even the nutritional yeast I was buying, which says ‘source of B12’ on the packet, turns out to have just 3.3ug per 100g.

So there has been undersupplementation for a while; no tingling or balance issues, but I also read that folate can mask some symptoms of B12 deficiency till it’s too late to reverse damage. Giving a deficiency dose for a while seems possibly a good idea. Based on the equation in your comment, 500mcg could be ok.

I just spoke with the doctor and they recommended 100-200mcg per day for 3-6 months. I guess 100mcg twice a day isn’t the intention there; it may be ok to stay with 200mcg once per day? (I could talk with the doctor again if needed.)

Thanks.

Ann,

In my last response to you, I originally wrote “2,000 mg” but I meant “2,000 µg.”

> How long do you think 100mcg per day would take to restore a deficiency for a child or teen?

It should start to improve their B12 status within days. Are they having symptoms of B12 deficiency? How much do they weigh?

Thanks, it’s difficult with teens also as they are expected to have acne.

How long do you think 100mcg per day would take to restore a deficiency for a child or teen?

The system for testing here seems to be that B12 and folate should be tested together, and if B12 levels are abnormal, then homocysteine is automatically checked. MMA testing may also be then funded. This seems not to take into account the way that if folate is adequate, it can mask low B12 symptoms and results, especially if MMA isn’t tested from the outset.

Do you think it’s possible to see from B12, folate and homocysteine results alone that B12 deficiency is being masked by folate?

Ann,

I’m not aware of any evidence that 2,000 µg twice a day for 2 weeks is dangerous for children or teens. There are no upper limits set by the Institute of Medicine. However, the subject hasn’t been studied extensively. In adults, there are rare cases of cobalt sensitivity that appears as acne; these are thought to normally resolve upon ceasing the higher doses but it hasn’t been formally studied.

A prudent method would be to assume that the 2,000 mcg applies to someone weighing 150 lbs and to extrapolate to the weight of the child or teen for a lower dose (lower dose = 2,000 * child’s weight / 150) and then rounding to an amount that’s practical by either cutting the tablets in halves or quarters or buying smaller doses. And monitor for any facial changes. That probably sounds scary—it’s very rare, but still worth monitoring. Or, you can just opt for much lower, but not inconsequential, amounts like 100 µg/day. µg = mcg = microgram

And is there any risk of taking the high dose for a couple of weeks, without testing whether there is deficiency or not?