B12 injection not proven to increase energy, metabolism

Feeling sluggish? Gaining weight? What you need is a shot in the arm, claim advertisers for trendy vitamin B12 injections. Don’t let marketers needle you. “If medical testing confirms that an individual has a vitamin B12 deficiency, a vitamin B12 supplement will help. But if a B12 deficiency has not been identified by a physician or primary care doctor, there is no need to waste energy and money on B12 shots,” says a clinical dietitian.