Vitamin B12 is a water-soluble vitamin that is required for the formation of DNA and red blood cells. It is also important for brain health and provides energy for the body. Vitamin B12 cannot be made by the body, which means that it needs to be obtained from food, supplements, or a combination of both.

Which foods contain vitamin B12?

Vitamin B12 is found primarily in meat, eggs, and dairy products. There are very few plant-based products that naturally contain vitamin B12, and certainly not at levels that could be considered nutritionally significant. Some types of seaweed naturally contain very small amounts of vitamin B12. There are also several fortified plant-based foods that contain vitamin B12. Some brands of cereals, bread, and plant-based milk have been fortified with vitamin B12. Check the label to find out if it has been added.

One of the foods with the highest levels of vitamin B12 is beef liver. Other significant food sources include clams, tuna, fortified nutritional yeast, salmon, beef, dairy products, and vitamin B12-fortified foods.

Vitamin B12 deficiency is not limited to vegetarians and vegans

It’s not only vegetarians or vegans who are at risk for having a vitamin B12 deficiency. There are two main reasons you could be deficient in this vitamin:

  1. You don’t get enough vitamin B12 from your diet
  2. You’re not absorbing enough of the vitamin into your body

Ineffective absorption can be common in older people if they have insufficient stomach acid. It’s also common in those who have had weight loss surgery.

People who eat meat regularly but aren’t absorbing the vitamin properly could wind up with a deficiency. There are many factors that could contribute to a lack of absorption. These include medications that interfere with absorption and certain health conditions. Pernicious anemia is a common cause of vitamin B12 deficiency in the elderly.

Vitamin deficiency anemia

Vitamin deficiency anemia is caused by insufficient levels of certain vitamins. If you have vitamin deficiency anemia it could be an indication of a vitamin B12 deficiency, or a deficiency in another vitamin, such as folate, or vitamin C.

Signs and symptoms of vitamin B12 deficiency

There are several possible signs and symptoms of vitamin B12 deficiency, some of which are summarized below.

1. Feeling tired and weak

It’s common for a person with a vitamin B12 deficiency to feel fatigued and weak. This is due to the role of vitamin B12 in the production of red blood cells. Red blood cells carry oxygen to your cells, so you’re likely to feel very tired with an inadequate supply of it.

It’s important to realize that fatigue and weakness could be symptoms of many potential health conditions and issues or deficiencies in other vitamins. For example, a vitamin D deficiency can also cause fatigue. [Find out more in “6 Common Signs of Vitamin D Deficiency”].

2. Oral health issues

Vitamin B12 is an important component of oral health. People with low levels of vitamin B12 could present with one or more signs related to oral health. These include glossitis and mouth ulcers. Glossitis, a condition in which the tongue is inflamed, feels painful and can make your tongue appear red, swollen, and abnormally smooth.

3. Pale or jaundiced skin

A person with a vitamin B12 deficiency may appear pale. Their skin and the whites of their eyes could also have a yellow tinge, known as jaundice. Again, these signs are related to problems with the production of red blood cells.

4. Problems related to brain and mental health

A vitamin B12 deficiency can affect cognitive performance at work and in everyday life. A person with a deficiency may experience memory loss, confusion, or general difficulty with cognitive tasks such as concentration, reasoning, and thinking.

Studies have shown that adequate vitamin B12 levels are crucial for cognitive function. Vitamin B12 levels are an important predictor of cognitive decline in older adults, and could be a risk factor for diseases such as Alzheimer’s and dementia.

A vitamin B12 deficiency is only one tiny aspect of nutrition that can affect brain health. An optimal balance of macronutrients and micronutrients (including B12) is important. As well, specific food choices and behaviors can play an important role in a person’s mental health. [Find out more in “You Are What You Eat: The Impact Nutrition Plays on Mental Health].

5. Tingling or loss of sensation in the hands and feet

Low levels of vitamin B12 in the body may present as nerve-related problems such as numbness or tingling in the hands and feet. One study found that decreased sensation and proprioception in the lower extremities were the most common nervous-system-related symptoms in patients with vitamin B12 deficiency.

6. Issues with balance and dizziness

Vitamin B12 deficiency can affect the central nervous system in many ways. A lack of B12 may cause a person to feel dizzy and lose their balance. This could result in problems with walking, or even sitting without support.

7. Vision disturbances

Less commonly, a person with a vitamin B12 deficiency may experience visual disturbances. It’s worth checking vitamin B12 status in a person experiencing problems with their vision. If a lack of vitamin B12 is causing the problem, early identification is crucial. Vitamin levels can be replenished to help prevent or reverse any damage to the optic nerve.

In summary

Many of the signs and symptoms of vitamin B12 deficiency could be indicative of a different health issue altogether. Just as a vitamin D deficiency could cause a person to feel weak and fatigued (as mentioned earlier), an iron deficiency could present in many of the same ways as a vitamin B12 deficiency. Some of the shared potential symptoms of a vitamin B12 or an iron deficiency include fatigue, weakness, poor concentration, and pale skin. [Find out more in “10 Signs and Symptoms of Iron Deficiency”].

The best way to find out if you have a vitamin B12 deficiency is by getting tested, which you can arrange through your doctor. Early recognition of the potential signs and symptoms of a vitamin B12 deficiency is also very important. This can help prevent the more long-term and serious manifestations of this deficiency.