Symptoms if You Take Too Much Vitamin B12 Severe anxiety from small doses of b12 When vitamin B12 levels drop, symptoms like fatigue, headaches, muscle weakness, and depression can appear, but diagnosis can be tricky since these overlap with many other conditions. #vitamins #vitaminb12 #Symptoms #healthtips #wellbeing # Why Do I Feel Worse After My B12 Injection? Causes & Management Bolt Pharmacy Taking Vitamin B12? Read this first. While B12 is often hailed as a safe energy and brain booster, many real users are reporting unexpected side effects including anxiety, insomnia, Are B12 Shots Safe? Royal Palm Beach Medical Group