Are you constantly feeling drained, no matter how much you sleep? Do you struggle with brain fog, forgetfulness, or strange sensations like pins and needles? You might chalk it up to stress, aging, or just a busy life. But what if the root cause is a simple, yet critical, nutrient deficiency? I’m talking about Vitamin B12, a powerhouse nutrient essential for the health of your nerves, the formation of your red blood cells, and the very function of your brain. A deficiency in this vitamin, also known as cobalamin, is surprisingly common, affecting millions of people. Because the body can store B12 for years, a deficiency can creep up on you slowly, with subtle symptoms that are often dismissed or misdiagnosed. This article will walk you through 15 of the most common—and often overlooked—signs that you might be running low on this vital nutrient.