You may be low on vitamin B12 without knowing it: 9 subtle signs that often appear long before fatigue

Most people assume a B12 problem is easy to identify. You picture someone pale, exhausted, barely able to get through the day. But that's usually the late stage of the story, not the beginning. Long before fatigue sets in, B12 deficiency tends to whisper through a string of odd, easy-to-dismiss symptoms — tingling fingers, a weird taste in your mouth, forgetfulness you chalk up to a busy week. And because those signs look so ordinary, most of us shrug them off for months, sometimes years, before anyone thinks to check a blood report.Why B12 deficiency is rising even among younger adultsFor a long time, B12 deficiency was treated as an older person's problem, tied to age-related drops in stomach acid or long-term use of drugs like metformin.