29yr male.taking monthly b12 neurobianforte shots-1000mcg.but i get tired in 20days.can i take higher dosage?how much time would it take for recovery?

Recheck B12 level: Before increasing your dose of vitamin B12 supplementation, you should have your vitmain B12 level rechecked to make sure that it has not yet normalized. If your vitamin B12 level has normalized and you're still feeling tired, then there may be other causes for your lack of energy that should be discussed with your primary care physician. http://www.nlm.nih.gov/medlineplus/ency/article/002403.htm

Are you vegetarian?: Vegetarians routinely have lower B12 levels, and may need shots or sublingual tablets to supplement. So work with your doctor to get at the level needed to make up the deficiency based on your lab results. You want to make sure you can absorb B12 too, so shots, and SL are best. If still low, look at why you're demethylating faster, and fix the cause first.

Vit B12 def: Do you have pernicious anemia or vegetarian. Though recommended to be given monthly, Most patients who respond due report the waning effect of the energy boost after 2 weeks. Hence I repeat the injection in such patients after two weeks. Vitamin B12is water soluble hence not widely distributed in body tissues hence can be easily excreted