Vitamin B12 is an essential nutrient that plays a vital role in producing red blood cells, supporting healthy nerve function, and helping the body make DNA. Since the body cannot produce vitamin B12 on its own, it must be obtained through food or supplements. Natural sources include meat, fish, eggs, and dairy products, so people who eat little or no animal-based foods may have a higher risk of deficiency unless they consume fortified foods or take supplements.

One of the first signs of a vitamin B12 deficiency is ongoing fatigue. Without enough vitamin B12, the body may struggle to produce healthy red blood cells that carry oxygen efficiently throughout the body. Other early symptoms can include weakness, shortness of breath, dizziness, and difficulty concentrating, which are often mistaken for stress, poor sleep, or a busy lifestyle.

As the deficiency becomes more severe, additional symptoms may appear. These can include pale or slightly yellowish skin, a sore or swollen tongue, mouth discomfort, and tingling or numbness in the hands and feet. Because vitamin B12 is important for nerve health, low levels can also affect the nervous system and may contribute to memory problems, irritability, reduced focus, or slower thinking in some people.

A simple blood test can help determine whether your vitamin B12 levels are low. Treatment depends on the underlying cause and may involve increasing vitamin B12-rich foods, taking oral supplements, or receiving injections prescribed by a healthcare professional. Early diagnosis and treatment can help prevent complications and restore healthy vitamin B12 levels.