During the lockdown, I started feeling extremely fatigued. We consulted a doctor and she ordered some tests. We found out that my Vitamin B12 levels were lower than normal. The doctor prescribed some supplements and then I started feeling better. This made me curious to learn and study more about Vitamin B12.
Vitamin B12 is a vitamin that is naturally present in some foods, added to others, and available as a dietary supplement and a prescription medication. Vitamin B12 exists in several forms and contains the mineral cobalt, so compounds with vitamin B12 activity are collectively called “cobalamins”.
Vitamin B-12 is a water-soluble vitamin, like all other B-vitamins. This means it can dissolve in water and travel through the bloodstream. The human body can store vitamin B-12 for up to four years. Any excess or unwanted vitamin B-12 is excreted in the urine. Vitamin B-12 is the largest and most structurally complicated vitamin. It occurs naturally in meat products and can only be industrially produced through bacterial fermentation synthesis.
Vitamin B12 is a nutrient that helps keep the body’s nerve and blood cells healthy and helps make DNA, the genetic material in all cells. Vitamin B12 also helps prevent a type of anemia called megaloblastic anemia that makes people tired and weak. Vitamin B-12 is crucial to the normal function of the brain and the nervous system. It is also involved in the formation of red blood cells and helps to create and regulate DNA.
The metabolism of every cell in the body depends on vitamin B-12, as it plays a part in the synthesis of fatty acids and energy production. Vitamin B-12 enables the release of energy by helping the human body absorb folic acid.
The human body produces millions of red blood cells every minute. These cells cannot multiply properly without vitamin B-12. The production of red blood cells reduces if vitamin B-12 levels are too low. Anemia can occur if the red blood cell count drops.
Because your body is capable of storing several years’ worth of vitamin B-12, deficiency is rare. However, if you follow a vegetarian or vegan diet, you might be prone to deficiency because plant foods don’t contain vitamin B-12. Older adults and people with digestive tract conditions that affect absorption of nutrients also are susceptible to vitamin B-12 deficiency.
- Avoiding animal products. People who do not eat meat, fish, poultry, or dairy are at risk of becoming deficient in vitamin B12, since it is only found naturally in animal products. Studies have shown that vegetarians have low vitamin B blood levels.  For this reason, those who follow a vegetarian or vegan diet should include B12-fortified foods or a B12 supplement in their diets. This is particularly important for pregnant women, as the fetus requires adequate vitamin B12 for neurologic development and deficiency can lead to permanent neurological damage.
- Lack of intrinsic factor. Pernicious anemia is an autoimmune disease that attacks and potentially destroys gut cells so that intrinsic factor is not present, which is crucial for vitamin B12 to be absorbed. If vitamin B12 deficiency ensues, other types of anemia and neurological damage may result. Even the use of a high-dose B12 supplement will not solve the problem, as intrinsic factor is not available to absorb it.
- Inadequate stomach acid or medications that cause decreased stomach acid. A much more common cause of B12 deficiency, especially in older people, is a lack of stomach acid, because stomach acid is needed to liberate vitamin B12 from food. An estimated 10–30% of adults over the age of 50 have difficulty absorbing vitamin B12 from food.
- Intestinal surgeries or digestive disorders that cause malabsorption. Surgeries that affect the stomach where intrinsic factor is made, or the ileum (the last portion of the small intestine) where vitamin B12 is absorbed, can increase the risk of a deficiency. Certain diseases including Crohn’s and celiac disease that negatively impact the digestive tract also increase the risk of deficiency
Vitamin B12 deficiency can be slow to develop, causing symptoms to appear gradually and intensify over time. It can also come on relatively quickly. Given the array of symptoms a vitamin B12 deficiency can cause, the condition can be overlooked or confused with something else. Vitamin B12 Deficiency symptoms may include:
- strange sensations, numbness, or tingling in the hands, legs, or feet
- difficulty walking (staggering, balance problems)
- a swollen, inflamed tongue
- difficulty thinking and reasoning (cognitive difficulties), or memory loss
While an experienced physician may notice the symptoms and be able to detect a vitamin B12 deficiency with a good interview and physical exam, a blood test is needed to confirm the condition. It’s a good idea to ask your doctor about having your B12 level checked if you are a strict vegetarian or have had weight-loss surgery or have a condition that interferes with the absorption of food. Early detection and treatment is important. If left untreated, the deficiency can cause severe neurologic problems and blood diseases.
You can get vitamin B12 in animal foods, which have it naturally, or from items that have been fortified with it. Animal sources include dairy products, eggs, fish, meat, and poultry. If you’re looking for a food fortified with B12, check the product’s Nutrition Facts label. You can also take vitamin B12 supplements.
This article provides information that should not take the place of medical advice. You must talk to your healthcare providers (doctor, registered dietitian, pharmacist, etc.) about questions regarding Vitamin B12 and what may be best for your overall health.