Vitamin B12 is an essential nutrient that is required for a variety of important functions in the human body, including the production of new DNA, the maintenance of healthy nerve and blood cells, and the breakdown of proteins and fats for energy. While most individuals get enough vitamin B12 through their diet, some may be at risk of a deficiency due to certain health conditions, especially as they age.
Vitamin B12, also known as cobalamin, is one of the B-complex vitamins that cannot be produced by the body and must be obtained through the diet. It is primarily found in animal products, such as meat, poultry, fish, and eggs, and is more easily used by the body in certain forms. For example, dairy products are a great source of vitamin B12, and supplements are also readily available.
According to the National Institutes of Health, teens and adults need approximately 2.4 micrograms of vitamin B12 per day, while pregnant individuals require around 2.6 micrograms, and those who are breastfeeding need 2.8 micrograms. Infants and children need 0.4 to 1.8 micrograms, depending on their age.
A deficiency in vitamin B12 can have several negative effects on the body. For example, low B12 levels can lead to a type of anemia, or low blood count, characterized by macrocytic blood cells that become large before a person becomes anemic. Symptoms of anemia may include tiredness, pale skin, shortness of breath, loss of appetite, headaches, and a fast or irregular heartbeat.
In addition, vitamin B12 is critical for nerve cells to function properly. A deficiency in B12 can affect the central nervous system or peripheral nerves that go to the rest of the body, resulting in tingling sensations, depression, irritability, confusion, vision changes, memory loss, and problems with balance. Pregnant individuals who lack vitamin B12 and folate may have a baby with a neural tube defect, which occurs when the brain or spinal cord develops incorrectly.
B12 is also necessary for the creation of new DNA, so low B12 and folate levels can cause DNA damage, leading to diseases like cancer, heart disease, stroke, and dementia. The body stores extra vitamin B12 in the liver, so it may take years for someone to develop symptoms from a B12 deficiency.
Certain health conditions or lifestyle factors can increase an individual’s risk of B12 deficiency. For example, individuals who do not consume enough vitamin B12 may follow a strict vegan or vegetarian diet and do not take a supplement or eat other foods fortified with vitamin B12. Infants of pregnant or breastfeeding people who don’t get enough vitamin B12 are also at risk. People who have had weight-loss surgery or other stomach and intestinal surgeries, low stomach acid due to aging or medications, inflammation in the stomach or small intestine from gastritis, celiac disease, or Crohn’s disease, pernicious anemia, and those taking metformin for diabetes, or drinking alcohol can also have difficulty absorbing enough B12.
A healthcare provider can test an individual’s B12 blood level if they have a risk factor for deficiency. Physical exams can also provide clues, but individuals may not exhibit symptoms or obvious changes on an exam. Blood tests can determine anemia, B12 levels, and the size of blood cells. More specialized tests may be conducted for advanced disease or if autoimmune disease is suspected.
Treatment for B12 deficiency will depend on the severity and cause. Oral, nasal, or injected forms of B12 treatment may be necessary. If the deficiency is not severe and was caused by a lack of vitamin B12 in the diet, taking a supplement or adding more B12-rich foods to the diet may be sufficient.
However, if the deficiency is severe or caused by an underlying medical condition that impairs absorption of B12, more aggressive treatment may be necessary. Here are some possible treatments for B12 deficiency:
- Vitamin B12 supplements: Taking high-dose vitamin B12 supplements can help restore normal levels of the vitamin in the body. This can be done orally, with sublingual (under-the-tongue) tablets, or with injections.
- Dietary changes: Adding more B12-rich foods to the diet can help increase intake of the vitamin. Some good dietary sources of vitamin B12 include meat, fish, poultry, eggs, dairy products, and fortified breakfast cereals.
- Intramuscular injections: If the deficiency is severe or caused by an absorption problem, intramuscular injections may be necessary to bypass the digestive system and deliver the vitamin directly into the bloodstream.
- Nasal spray: A prescription nasal spray containing vitamin B12 can also be used to treat deficiency, particularly for those who cannot tolerate injections.
- Transdermal patches: Transdermal patches containing vitamin B12 are also available, which can be applied to the skin to deliver the vitamin directly into the bloodstream.
It’s important to note that while B12 deficiency is a common problem, it can have serious health consequences if left untreated. Symptoms such as fatigue, weakness, and neurological problems can worsen over time, leading to permanent nerve damage and other complications. Therefore, it’s important to seek medical advice if you suspect you may be deficient in vitamin B12.