Cobalamin deficiency, also known as Vitamin B12 deficiency, occurs when the body lacks sufficient amounts of this essential nutrient. Cobalamin is crucial for producing red blood cells, maintaining nerve function, and synthesizing DNA. A deficiency can lead to symptoms such as fatigue, weakness, and neurological issues. This condition is often caused by inadequate dietary intake, particularly in individuals following a strict vegan diet, as Vitamin B12 is primarily found in animal products. Additionally, certain medical conditions, such as pernicious anemia or gastrointestinal disorders, can impair absorption, leading to deficiency even with adequate dietary intake.