can you overdose on vitamin b12 injections Take Too Much B12? and Side Effects Vitamin B12: Overdose and Side

Safety and efficacy in humans remain unestablished

Rotate injection sites (abdomen, thighs, upper arms) to reduce local irritation [7]

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Its commonly found in animal-based foods such as meat, fish, dairy, and eggs

So we can excrete HUGE amounts of B12 in a short time if it is extraneous to the amount we currently need