June 13, 2016

We’re told to take our vitamins, but that’s not always the whole story.


Are you feeling more tired than usual or rundown? If you have certain conditions, take certain medications or follow a vegan or vegetarian diet, you may be more at risk for a vitamin B12 deficiency, which can lead to fatigue and other issues. This essential nutrient cannot be synthesized in the body and is vital for normal function.


What are the symptoms of low B12 levels?

“Vitamin B12 deficiencies initially manifest as paleness of the skin, fatigue and weakness,” says Marilyn Holmes, M.S., R.D., LDN, associate director at the Vanderbilt Recreation and Wellness Center. “As the deficiency progresses, nerves can be affected, resulting in numbness, tingling or pain in your extremities.” If you are experiencing any of these symptoms, talk to your primary care provider.


What conditions or medications might cause a B12 deficiency?

If you have any of the following conditions, you should talk to your doctor about testing your B12 levels: gastritis, autoimmune diseases (including type 1 diabetes) HIV, alcoholism, Crohn’s disease or celiac disease. You may also be at risk if you have had part or all of your intestine removed or had weight-loss surgery or if you take acid-reducing medications or drugs for managing diabetes.


Why do vegans or vegetarians need to be concerned about their B12 levels?

B12 is not naturally found in any plant foods, and it is the nutrient most lacking in vegetarian diets. So if you eat a strict vegan diet or — if as a lacto-ovo vegetarian — your egg and dairy consumption is limited, you should take a supplement or eat fortified grains. “The recommended dietary allowance (RDA) for adults is 2.4 micrograms a day,” Holmes says. “The RDA for women who are pregnant or breastfeeding is higher.”


What is the solution for a vitamin B12 deficiency?

For some people, an oral supplement might solve the issue. However, Holmes cautions, “Persons with low amounts of hydrochloric acid in the stomach may not be able to absorb vitamin B12. Hydrochloric acid is a component of gastric acid, which aids in the breakdown of protein. Also, persons unable to make a protein known as intrinsic factor are unable to absorb adequate amounts of B12.”


What are the alternatives to oral vitamins for people who cannot absorb B12?

Your primary care provider can provide B12 shots in his or her clinic if necessary. B12 is also available as a nasal gel and spray, as well as a liquid for administering under the tongue. “Discuss preferences with your primary care provider,” Holmes says, adding that the effectiveness of medication types vary and depending on your need may dictate the form(s) best for you.