Vitamin B12 is an essential nutrient for your health. This vitamin, also known as cobalamin, is a crucial ingredient for your red blood cells formation. It’s also involved in cell metabolism and DNA production, and contributes to keeping your nerves and blood cells in good condition. Most people get enough of it, although some individuals struggle to absorb it.
Before continuing, please note that the following text does not constitute any form of medical advice or diagnosis, and you should not rely on it as a substitute for actual guidance by your doctor or any qualified health professional. Talk to your doctor if you think you may be suffering B12 deficiency or want to make sure you get enough of it.
Where is vitamin B12 present?
Foods that are naturally high in B12 are of animal origin exclusively. Good sources of B12 include seafood (like clams or scallops), meat (offal, like liver or kidneys), and fish (salmon or herring, for instance). Eggs also contain B12. Some people, like vegans, may need to take supplements to ensure they are getting enough vitamin B12, although this should always follow advice by a doctor or dietitian. They can also get it from some artificially fortified foods, namely breakfast cereals or fortified yeast extract.
As the National Library of Medicine explains, vitamin B12 is a water-soluble nutrient that can be stored for years in the liver. Most adults should aim for 2,4mcg (micrograms) of B12 daily, according to the ODS, 2,6 in the case of pregnant teens and women and 2,8 if they are breastfeeding. This is because during pregnancy serum vitamin B12 levels often drop, usually returning to normal after giving birth.
Since the human body is able to store around 1 to 5 mg of this nutrient (which is roughly 1,00 to 2,000 times the amount that most people get each day), deficiency symptoms can take years to show. Most people get enough of vitamin B12. The ODS cites several analysis claiming that up to 6% of adults younger than 60 years suffer from deficiency in the United States and the United Kingdom. The percentage is 20% for people aged 60 or older, because older people tend to struggle more to absorb this vitamin.
Social inequality is known to play a role in the overall distribution of B12 deficiency: an analysis by the National Health and Nutrition Examination Survey 2015-2016 (NHANES) found that those of low socioeconomic status, women and non-Hispanic Blacks were more prone to suffer deficiency.
What causes B12 deficiency?
Many people link B12 deficiency to a poor diet, but this is hardly the only reason for this phenomenon. As the NIH’s Office of Dietary Supplements (ODS) explains, deficiency can also be caused by a difficulty absorbing this nutrient from foods or some conditions like pernicious anemia. Some types of gastrointestinal surgeries may also result in this deficiency. Some medications can also have this effect, like metformin or proton pump inhibitors. People who struggle to absorb B12 present in food can absorb free B12 in supplements, so the deficiency is less severe compared to those who suffer from pernicious anemia, which renders them unable to absorb this nutrient in any form. Finally, some people are born with congenital conditions that prevent proper absorption.
This deficiency, ODS authors note, includes a series of health conditions, most notably megaloblastic anemia. Because vitamin B12 is essential for normal nerve and red blood cell function, a lack thereof can affect red blood cells and cause a condition called megaloblastic anemia, where red blood cells are larger and malformed. Red and white blood cells are also fewer in number. Symptoms include fatigue, pale skin, palpitations, weight loss and infertility, and deficiency is also known to play a role in the development of dementia. A lack of this nutrient can also affect the neurological system by causing changes like numbness or tingling in the hands and feet. These changes can appear before actually developing anemia, which is why it’s important to detect deficiency in early stages, experts say.