B12 deficiency: Symptoms may include urinary retention and incontinence Express.co.uk Taking B12 for energy? The evidence says you're probably wasting your money. B12 is only powerful in one situation: when you're deficient. Not tired. Not run down. Not a bit low on Vitamin B12 deficiency, sometimes called cobalamin deficiency, happens when your body is either not getting enough or not absorbing enough vitamin B12 from the foods you eat. Vitamin B12 is an important B12 Shots at Home: How, Where & How Often to Inject Yourself AZ IV Medics Vitamin B12: Urine discolouration could mean you're talking too many supplements Express.co.uk