I almost dread to ask this, but for the people who suffered side effects from methylcobalamin, had the vitamin been exposed to light?
I'm wondering if that is a factor in creating impurities and causing side effects (particularly acne). I'm just not sold on the detox explanation.
Apparently methylcobalamin + air + water = aquocobalamin + formaldehyde. Formaldehyde can cause skin complaints.
I had had no warning to keep the sublingual from light. No mention of it from my doctor and no directions on the jar. It came in a thin white plastic jar. I later tried a methylcobalamin spray in a dark bottle which I kept from light but still had side effects.
I had a similar problem with hydroxocobalamin in a white jar as well. I am testing out a pure liquid form now and keeping it in the dark! So far, so good, but it's early.
At the risk of bringing side effects up yet again :-p, however, they really can be severe for some people and since there are so many conflicting theories as to why they happen, I think it's worth discussing now and then.