by Chris Prakash, MD
Q: I have been feeling very tired lately. My friend told me that her doctor gives her B12 shots and I should do the same. Do you think that is a good idea?
Dr. Chris Prakash
A: I am sure that your friend has good intentions with that advice. I also know that a lot of people believe that vitamin B12 injections give them “pep” and alleviate fatigue. However, scientific data does not back this up. For people who are not deficient in B12, there is no evidence whatsoever that supplemental B12 helps. I recommend that you be evaluated by your doctor for possible causes of fatigue, and if it turns out that you lack B12, you may very well feel better with supplementation.
What is B12?
B12 is an essential vitamin with an important role in optimal functioning of various organ systems in the body. Most of all, it is needed for the development and maintenance of a healthy nervous system, the production of DNA and formation of red blood cells.
What are the symptoms of B12 deficiency?
A B12 deficiency can manifest in various ways. It can result in anemia, which can be picked up on a routine blood test. But the less dramatic symptoms of B12 deficiency may include muscle weakness, fatigue, shakiness, unsteady gait, incontinence, depression, and poor memory.
B12 deficiency can mimic dementia!
Sometimes, we may notice our elderly parents or grandparents becoming increasingly confused, and having short term memory loss. Immediately, dementia, or even Alzheimer’s comes to mind. In fact some of these people may even be treated for dementia, before it is recognized that they are deficient in vitamin B12. A B12 level is an easy blood test, and can prevent misdiagnosis, and unnecessary treatment.
Labs differ in what they consider normal B12 levels, but most experts consider a level below 400 needs to be treated.
Where do we get B12?
In its natural form, B12 is present in significant amounts only in animal foods, most prominently in liver. Other good food sources include red meats, turkey, fish and shellfish, dairy products, eggs and chicken. Vitamin B12 is generally not present in plant foods, but fortified breakfast cereals are a readily available source of vitamin B12 with high bioavailability for vegetarians.
Recommended dietary amounts of B12 vary: 2.4 micrograms daily for those ages 14 and older, 2.6 micrograms for pregnant women and 2.8 micrograms for nursing women (National Academy of Sciences). Usually, these levels are easily obtained from a well-balanced diet containing animal protein.
Who is at risk of B12 deficiency?
Vitamin B12 deficiency rises with age, to about 15% of elderly people. The rate is also much higher among people who don’t eat meat or dairy products, people with intestinal absorption problems, people taking acid-blockers and those with diabetes who take the drug Metformin. Heavy drinkers are also at increased risk of B12 deficiency.
Some people lack Intrinsic Factor (needed for absorption of B12), especially in people with an autoimmune disorder called pernicious anemia. This results in B12 deficiency.
How do we treat B12 deficiency?
Although injections of B12 work fast to correct a B12 deficiency, considerable evidence indicates that, in large enough doses, sublingual (under-the-tongue) tablets of B12 may work as well as injections, even for those with pernicious anemia.
Most often, a daily supplement of 2,000 micrograms is recommended for about a month, then lowered to 1,000 micrograms daily for another month, then lowered again to 1,000 micrograms weekly.
What is the role of Folic Acid?
Large doses of folic acid can mask a B12 deficiency and cause permanent neurological damage if normal levels of B12 are not maintained. This may be happening to a lot of elderly people due to the mandated folic acid fortification of foods. The folic acid masks the anemia and fatigue associated with B12 deficiency thus allowing the B12 deficiency to go undetected for a long time.
This information is strictly an opinion of Dr Prakash, and is not intended to replace the advice of your doctor. Dr Chris Prakash is a contributing columnist, and author of eParisExtra’s “The Doctor is In” column. He is a medical oncologist at Texas Oncology Paris. He is board certified in Internal Medicine, Oncology and Hematology. He lives in Paris, TX with his wife and two children, and can be reached at 9037850031, or Sucharu.prakash@usoncology.com