Vitamin B12: How important Is the Vitamin to Your Health?
If you recently developed frequent dizziness, an irregular heartbeat, or unexplained weight loss, you may believe that you have hypertension, atrial fibrillation, or another health condition. Instead of a more familiar health issue, it’s possible that you could have something that would surprise you: A vitamin B12 deficiency.
If you have a vitamin B12 deficiency, you are not alone. Vitamin B12 deficiency is a common problem that affects between 6 percent to 20 percent of the U.S. population. When left untreated, a B12 deficiency can affect overall health and quality of life.
Vitamin B12 is essential to the body because it supports the central nervous system and brain function, assists in forming healthy red blood cells, and in producing DNA and RNA.
The National Institutes of Health (NIH) recommends a daily B12 allowance of 2.4 micrograms for adults. The water-soluble vitamin is found in a variety of foods, including:
• Chicken, liver, beef, ham
• Fish and shellfish, such as clams, trout, salmon, tuna fish, and clams
• Low-fat milk, yogurt, and cheese
• Fortified breakfast cereal
B12 can also be added to other foods, taken as a dietary supplement, and prescribed as a prescription medication.
B12 Absorption is Key
The body absorbs vitamin B12 in a complex multistep process, Diane Cress wrote in an article for The Conversation.
According to Cress, an associate professor of nutrition and food science at Wayne State University in Detroit, Michigan, the process begins as soon as we put food in our mouths:
1. When we chew, our food mixes with saliva.
2. When the food is swallowed, a substance in saliva called R-protein—a protein that protects B12 from being destroyed by stomach acid—travels to the stomach along with the food.
3. Parietal cells in the stomach lining secrete stomach acid and a substance called “intrinsic factor,” both are important to B12 absorption. Stomach acid splits food and B12 apart. This allows B12 to bind to the saliva’s R-protein. Meanwhile, the intrinsic factor mixes with the stomach’s contents and travels with them into the duodenum, the first part of the small intestine.
4. Once in the duodenum, pancreatic juices release B12 from R-protein and give it to intrinsic factor. This pairing allows B12 to be absorbed into cells, where it can support nerve cells and form healthy red blood cells.
A breakdown at any of these steps can result in a B12 deficiency, Cress says. For example, antidepressants, opioids, decongestants, and other medications can cause dry mouth, which means glands in the mouth are not producing enough saliva. Without saliva, B12 will not bind to the saliva’s R-protein, which hinders the body from absorbing the vitamin.
In addition, damage to the stomach lining due to gastric surgery, chronic inflammation, and other conditions can prevent the production of gastric acid and intrinsic factors, both of which are critical for B12 absorption.
Other Causes of Vitamin B12 Deficiency
Besides the breakdown of the multistep absorption process, there are other common causes of a B12 deficiency:
• Not eating enough animal products or taking supplements. People who are on a vegan diet (meaning they do not eat meat, fish, or dairy products) and do not take vitamin supplements can have a vitamin B12 deficiency.
• Chronic diseases. Crohn’s disease, ulcerative colitis, and other conditions that interfere with the body’s ability to digest food and absorb B12 properly can cause a B12 deficiency.
• Age. Older adults are at risk of B12 deficiency due to age-related reduction in stomach acid, which the body needs to absorb vitamin B12.
• Certain medications. Studies have found that long-term use of Metformin, a drug prescribed to more than 92 million people to treat type 2 diabetes, can lower vitamin B12 levels. Also, proton pump inhibitors (PPI), which are common medications used to treat heartburn and acid-related disorders, contribute to reduced levels of B12. One observational study analyzed the health records of nearly 25,956 patients diagnosed with vitamin B12 deficiency. Researchers found that people who took PPIs for more than two years had a 65 increased risk of vitamin B12 deficiency.
Signs, Symptoms, and Treatment of B12 Deficiency
Medical experts say a vitamin deficiency develops gradually over several months to years and becomes worse over time. Identifying a vitamin B12 deficiency can stump doctors because the signs and symptoms are similar to other common chronic health conditions. Some signals of a B12 deficiency include:
• Difficulty maintaining balance
• Irregular heartbeats
• Memory loss
• Numbness or tingling in the hands and feet
• Pale or yellowish skin
• Personality changes
• Shortness of breath
• Weight loss
Cress said even though she teaches nutrition and food science to college students, she missed a B12 deficiency in her dog. Scout, a hyper yellow Lab puppy, started to get tired all of the time. It wasn’t until the veterinarian ran a blood test for B12 and a complete blood count that she discovered that Scout had a vitamin B12 deficiency.
Getting a blood test to measure B12 levels is a good starting point for humans, too. Cress says that a “proper lab workup and discussion with a physician are necessary to discover or rule out whether inadequate B12 levels could be at play.”
Once discovered, treatment for a vitamin B12 deficiency can be oral, applied under the tongue, administered through the nose, or taken the form of various types of injections, according to Cress.
“A B12 supplement or balanced multivitamin may be enough to correct the deficiency, as it was for Scout, but it’s best to work with a health care provider to ensure proper diagnosis and treatment,” Cress wrote.