Vitamin B-12 is a necessary nutrient for overall health. Most people in the United States get enough of this water-soluble vitamin from their food. However, aging and lifestyle choices, medical conditions, and medications can negatively affect the body’s ability to absorb B-12.
The human body requires this vitamin to maintain the central nervous system and DNA. B-12 is also vital for the body to keep red blood and nerve cells healthy. It also aids in brain function. In addition, the essential vitamin aids in the prevention of megaloblastic anemia, which is a blood disorder that causes weakness and fatigue.
Unfortunately, the body does not make this vitamin. Therefore, people must obtain B-12 through food or supplements. Harvard Health’s website explains that “some people don’t consume enough vitamin B-12 to meet their needs, while others can’t absorb enough, no matter how much they take in.” Failure to absorb the vitamin results in deficiency, which is relatively common, especially in adults over 60.
Daily B-12 Recommended Quota
An average adult should get 2.4 micrograms of this vitamin daily to avoid becoming deficient. Health experts suggest people satisfy their daily B-12 quota by eating animal or fortified foods.

The National Institutes of Health (NIH) reports the following animal foods naturally contain this vitamin: fatty or oily fish, pork, beef, lamb, veal, and poultry.
Egg yolks, milk, and other dairy products also possess this vitamin. Beef liver and clams are some of the best B-12 sources.
No plant foods contain B-12 unless they are fortified, like some breakfast cereals and plant-based milk such as soy, almond, coconut, and cashew. Other fortified foods include nutritional yeast, tempeh (tempe), natto, yeast spreads, nori (purple laver), non-dairy yogurt, algae, and shitake mushrooms.
Jason Ewoldt, RDN, LD, a wellness dietitian at Mayo Clinic Healthy Living Program, explained that “even [older adults] who eat all foods may have difficulty absorbing enough vitamin B-12.”
Vitamin B-12 Absorption Deficiency
B-12 absorption begins in a person’s mouth. Next, saliva containing stomach acid separates the mineral from protein molecules. Finally, the vitamin is absorbed in the small intestine. When this part of the digestive system is not working correctly, the result could be a deficiency.

The liver stores excess B-12 for up to five years. Since the body requires small amounts daily, if a healthy person stops consuming the vitamin, it could take a few years before symptoms develop.
NOTE: B-12 and iron are distinctly different. The first is a vitamin, and the second is a mineral. Not only are the two separate in composition, but each function differently as a nutrient.
The NIH website indicates some people are more likely to become deficient than others. A strict vegetarian diet, anti-acid type medications, heavy drinking, and aging are examples of vitamin B-12 deficiency causes. Additional causes include autoimmune diseases and partial stomach or intestine-removal operations such as weight loss.
Strict vegetarians and vegans must pay attention to their diets. To ensure they do not suffer from B-12 deficiency, they must include fortified bread, cereals, or other grains. In addition, vegetarians should consider taking a daily supplement of this essential vitamin.
Those with a weight loss operation, such as a gastric bypass, are more likely to become B-12 deficient because the surgery removes or bypasses the end of the small intestine, interfering with the body’s ability to remove the vitamin from food.
Aging and Medical Conditions As Deficiency Causes

The body’s ability to absorb B-12 starts to lower at around 40. The malabsorption may be due to the low-level production of stomach acid needed to absorb the vitamin, typical in aging adults, even when they eat enough B-12 foods or take supplements.
However, children and younger adults, including those who are pregnant and breastfeeding, can develop B-12 deficiency.
People who use anti-acid medication chronically or take proton inhibitors for gastrointestinal disorders such as Prilosec, Tagamet, Zantac, and Prevacid are susceptible to B-12 deficiency. Another commonly prescribed medication that interferes with this essential vitamin absorption is Metformin, used to treat diabetes.
Medical conditions such as chronic gastritis, an autoimmune disorder, type 1 diabetes and thyroid, Crohn’s, and celiac diseases interfere with nutrient absorption. Those with a family history of B-12 deficiency also stand a higher chance of problems.
Doctors might overlook or misdiagnose the deficiency in aging adults. Leslie Kernisan, MD, MPH, reports that experts estimate about 20% of older adults may be low on B-12. “It’s often missed by doctors.”
Jullian Kubala, MS, explained: “Oftentimes, this is due to inadequate laboratory testing or because the symptoms are not specific to B-12 deficiency alone.” Specifically, other medical conditions’ symptoms and those of B-12 deficiency overlap.
B-12 Deficiency Symptoms and Treatments

The NIH reports that a person’s B-12 levels might be low if they feel tired or weak. They may also have headaches, pale skin, muscle cramps, loss of appetite, weight loss, heart palpitations, anemia, and infertility.
A person’s hands and feet might become numb or tingly, which could signal nerve problems. In addition, people might have “problems with balance, depression, confusion, dementia, poor memory, and soreness of the mouth or tongue.”
Health experts recommend seeking medical assistance if a person suffers from B-12 deficiency symptoms, is a vegetarian or on a restrictive diet, has had weight loss surgery, or has pancreas, intestine, or stomach problems — additionally, those on stomach acid reduction medication.
Kubala says that doctors can rule out the deficiency by ordering blood tests. These tests can include a CBC with a peripheral smear and B-12, folate methylmalonic acid (MMA), and homocysteine levels.
The healthcare professional will recommend the best treatment if the test results reveal low B-12 levels. These treatments may include oral or supplements to replace the missing essential vitamin. Otherwise, the doctor will treat and manage any unlying health condition causing the deficiency.
Physicians generally order B-12 injections for people who cannot properly absorb the essential vitamin from food or supplements. These include those who have had gastric bypass surgery or individuals with autoimmune disorders.
Written by Cathy Milne-Ware
Originally published on Guardian Liberty Voice
Sources:
Healthline: 9 Signs and Symptoms of Vitamin B12 Deficiency; by Julian Kubala, MS, RD, Medically Reviewed by Meredith Goodwin, MD, FAAFP
Better Health While Aging: How to Detect & Treat Vitamin B12 Deficiency in Older Adults; by Leslie Kernisan, MD, MPH
NIH: Vitamin B12: Fact Sheet for Consumers
Harvard Health Publishing: Vitamin 12 deficiency can be sneaky and harmful
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