Chance of B12 deficiency increases as people age


Dear Doctors: We moved recently, and my father, who lives with us, now has a new doctor. During his first appointment, she asked about his vitamin B12 levels and seemed surprised that this wasn’t a test that had already been done. My father is not a vegetarian, so why would this be important?

Dear Reader: Vitamin B12 is a nutrient that plays a vital role in some of the body’s most important functions. These include the development and performance of the central nervous system, the formation of healthy red blood cells and the synthesis of DNA.

And while the body needs B12, it cannot produce it. In its natural form, B12 is found in animal-based products. It is most abundant in liver, and is present in significant amounts in red meat, shellfish, fish and turkey. Eggs, chicken and dairy products also provide B12, but in smaller amounts.

You didn’t mention your father’s age in your letter, but his doctor’s concern for his levels of vitamin B12 suggests that he is an older adult. You’re correct that getting adequate B12 is a concern for vegetarians and vegans, whose diets eliminate natural sources of the vitamin. But getting enough B12 can become a challenge when people reach older age, as well.

In order to be available for absorption, B12 must be freed from the protein it is attached to. This takes place in the stomach, where hydrochloric acid severs the bonds. The vitamin is then combined with another protein made by the stomach, known as intrinsic factor. It is this combination that the body is able to absorb. But due to changes in digestion as we age, which includes a decrease in stomach acid production, the body’s ability to absorb B12 can decline. Regular use of antacids and ulcer medications can also interfere with B12 absorption.

The recommended daily intake of B12 for adults in 2.4 micrograms. However, the body is able to store up to 2,000 times that amount. That means it can take several years for symptoms of a deficiency to appear. When they do, these symptoms can be similar to some of the effects of aging. This can lead to them being ignored, or even misdiagnosed. Someone with a B12 deficiency may feel weak or tired, have trouble with balance or walking, experience numbness or tingling in the feet or hands, feel depressed, and experience confusion, memory problems or other changes to cognition.

Elizabeth Ko, MD and Eve Glazier, MD

The good news is that this type of deficiency is easily identified with a blood test. Initial treatment to correct a B12 deficiency usually involves much larger doses than the body actually requires. A health care provider may recommend B12 injections, sublingual (under the tongue) doses of the vitamin or B12 skin patches. This is typically followed with daily supplementation.

It is estimated that up to 20% of people over the age of 60 become deficient in this very important vitamin, so the concerns of your father’s new physician are well-founded.

The primary care physicians at UCLA Health offer everything from routine screenings and disease prevention to coordinated treatments for a wide range of health conditions. Talk to your provider about your concerns. Learn more and schedule an appointment.

(Send your questions to [email protected], or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)