During the summer of 2022, my dog Scout experienced a peculiar issue, vomiting consistently at 3 a.m. for several months. If you’re a dog owner, you’re likely familiar with the distinct sound. Complicating matters, she quickly consumed her vomit each time, making it challenging to pinpoint the cause.
After consulting with the vet, we initially suspected my hydrangeas as the culprit, but even efforts to keep Scout away from them proved ineffective. A new concern emerged as Scout began exhibiting constant fatigue, which was particularly alarming for a usually energetic yellow Lab puppy.
The mystery took a turn when Scout vomited up a hairball one day – not just any hairball, though. While hair typically passes through a dog’s digestive system without issue, this particular hairball was entangled around a brillo pad, too large to navigate through the system. Once this foreign object was removed, the nightly vomiting ceased. However, Scout still required treatment for an unexpected reason: the object had disrupted her body’s absorption of vitamin B12. Vitamin B12 is a crucial nutrient vital for the proper functioning of blood cells, nerves, and various critical processes in the body.
Despite being a registered dietitian teaching nutrition and food science to college students, I overlooked the B12 deficiency contributing to my puppy’s fatigue. This oversight highlights how even professionals can miss it, underscoring that doctors may similarly overlook B12 deficiency in people. Surprisingly common, affecting an estimated 6% to 20% of the U.S. population, B12 deficiency can evade detection.
B12 is a scarce nutrient in the diet, exclusively present in animal-derived foods. Fortunately, humans require only a minute amount—2.4 micrograms of B12 daily, equivalent to one ten-millionth of an ounce. This tiny quantity plays a significant role in maintaining overall health and quality of life. The subtle nature of B12’s impact underscores the importance of vigilance in recognizing and addressing deficiencies in both human and animal health.
Signs and Symptoms:
A predominant indicator of B12 deficiency is profound fatigue, reaching a level that significantly interferes with daily life activities.
Neurological symptoms are also common, encompassing tingling sensations in the extremities, confusion, memory loss, depression, and difficulties in maintaining balance. Importantly, some of these neurological effects can become permanent if the underlying vitamin deficiency is not addressed promptly.
Complicating matters, the symptoms of B12 deficiency are diverse, and healthcare providers may inadvertently overlook it, assuming other potential causes for the observed issues. Even with a seemingly healthy diet, the possibility of a B12 deficiency may be disregarded. In the case of my dog Scout, despite maintaining a well-balanced diet, I did not initially consider B12 deficiency as the root cause of her health problems. This underscores the importance of recognizing the varied symptoms and the need for thorough screening to ensure timely diagnosis and intervention.
B12 Absorption Process:
For those adhering to plant-based diets, research emphasizes the necessity of B12 supplements, commonly found in standard multivitamins. Surprisingly, even among the vast number of Americans who do consume B12, there’s a potential risk due to conditions that may impede the absorption of this crucial vitamin.
The absorption of B12 is a intricate, multi-step process commencing in the mouth and concluding at the far end of the small intestine. As we chew, our food blends with saliva, and a vital component called R-protein in saliva accompanies the swallowed food to the stomach. This protein serves as a protector, preventing B12 from being destroyed by stomach acid.
Within the stomach lining, specific cells known as parietal cells play a crucial role in B12 absorption. They release stomach acid, which is pivotal in separating food and B12, allowing the vitamin to bind to R-protein in saliva. Simultaneously, another substance called intrinsic factor combines with the stomach’s contents and travels to the duodenum, the initial segment of the small intestine. In the duodenum, pancreatic juices release B12 from R-protein, and intrinsic factor takes charge, facilitating B12 absorption into cells. This absorption is essential for maintaining nerve cells and forming healthy red blood cells.
A breakdown at one or more of these points in the absorption journey typically characterizes a B12 deficiency. This complexity underscores the need for a comprehensive understanding of the absorption process and the potential obstacles that may lead to deficiencies, even in those with seemingly sufficient B12 intake.
Risk Factors for B12 Deficiency:
- Dry Mouth and Medications: Saliva is essential for B12 absorption, and various medications, such as opioids, inhalers, decongestants, antidepressants, blood pressure drugs, and benzodiazepines like Xanax, can cause dry mouth, hindering B12 binding to R-protein and absorption. The high prevalence of prescriptions for these drugs, numbering easily in the millions annually, poses a substantial risk.
- Reduced Stomach Acid Levels: Anti-ulcer medications, commonly taken by hundreds of millions of Americans, diminish stomach acid levels. Research links the use of these drugs to B12 deficiency, though the necessity of the medication may outweigh this risk. Aging, affecting over 60 million individuals in the U.S. aged 60 and above, can further decrease stomach acid production, potentially compounded by the use of acid-reducing medications.
- Stomach Lining Damage: The specialized parietal cells in the stomach are crucial for B12 absorption, but damage to the stomach lining can impede the production of both gastric acid and intrinsic factor. Factors such as gastric surgery, chronic inflammation, or pernicious anemia, a condition characterized by fatigue and numerous symptoms, contribute to impaired stomach lining.
- Pancreas Dysfunction: Inadequate pancreas function is another contributor to B12 deficiency, with approximately one-third of patients with poor pancreas function developing this deficiency.
- Metformin Use: Metformin, a drug prescribed to around 92 million Americans for Type 2 diabetes, has been linked to B12 deficiency for decades, highlighting another common cause.
Understanding these diverse risk factors is crucial for healthcare providers to identify and address B12 deficiency promptly, especially considering the widespread use of medications and the prevalence of conditions that can compromise the absorption of this vital vitamin.
Treatment for B12 deficiency
While some health care providers routinely measure B12 and other vitamin levels, a typical well-check exam includes only a complete blood count and a metabolic panel, neither of which measures B12 status. If you experience potential symptoms of a B12 deficiency and also have one of the risk factors above, you should see a doctor to be tested. A proper lab workup and discussion with a physician are necessary to discover or rule out whether inadequate B12 levels could be at play.
In the case of my dog Scout, her symptoms led the vet to run two blood tests: a complete blood count and a B12 test. These are also good starting points for humans. Scout’s symptoms went away after a few months of taking oral B12 supplements that also contained an active form of the B vitamin folate.
In humans, the type of treatment and length of recovery depend on the cause and severity of the B12 deficiency. Full recovery can take up to a year but is very possible with appropriate treatment.
Treatment for B12 deficiency can be oral, applied under the tongue or administered through the nose, or it may require various types of injections. 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.
This article is republished from The Conversation, a nonprofit, independent news organization bringing you facts and trustworthy analysis to help you make sense of our complex world. The Conversation is trustworthy news from experts.