Is it safe to take spring valley chewable b12 2500 mcg more than directed? one doesn't work enough for me, how much is too much?

Yes, no toxicity: Yes, it's safe to take more but it's very unusual to need more. Vitamin B12 is considered to be non-toxic so there is no known dose that is "too much." However, it's not well-absorbed so taking more than 2500 mcg may not increase the amount you absorb. I'm wondering what you mean when you say one doesn't work for you- what symptoms do more relieve that one doesn't? See http://tinyurl.com/oc8up5z

Safe: Extra vitamin B12 will have no effect whatever on someone who has enough of the vitamin. Anyone who tells you otherwise is taking advantage of the human susceptibility to the placebo effect. If you are interested in "natural healing", get with an evidence-based holist in your community.