Australian researchers reported last month that up to one in every five nursing home residents may have vitamin B12 deficiency. This finding is staggering when you reflect on the potential effects this could be having on the quality of life of these residents and their families.
Symptoms of Vitamin B12 Deficiency
It is estimated that up to 70% of people who are deficient in vitamin B12 will have symptoms of anaemia, 10% of which can be life threatening. Other signs and symptoms of deficiency include a range of subtle and nonspecific symptoms that can be misdiagnosed or missed altogether. These symptoms include neuropsychiatric symptoms like numbness or tingling in the hands, subtle and overt cognitive changes, and dementia. There are even case reports of blindness and psychotic episodes caused by vitamin B12 deficiency.
There are some estimates that between 75% and 90% of deficient individuals will have a neuropsychiatric symptom, and in up to 30% of these people it will be their only symptom. While anaemia associated with such a deficiency is reversible, neuropsychiatric symptoms may not be. Importantly though, they can be prevented.
Preventing Vitamin B12 Deficiency
As vitamin B12 is not made by the body, the first step is to pick a dietary source: meat, dairy and eggs. In recent times fortified foods have also become available, including soy milks and cereals. The recommended daily intake in many countries is 2.4 micrograms, which is equivalent to about 100g of lamb or beef, 4 large eggs, or approximately 2 cups of milk. Vitamin B12 is found exclusively in animal products and to date there have not been any naturally occurring reliable plant sources, despite internet rumours of its existing in mushrooms.
Absorbing Vitamin B12
While on average many people consume adequate amounts of B12 in their diet, a substantial proportion of people cannot absorb it properly. Medications, parasitic and bacterial infections, gastric defects and pancreatic insufficiency are just some of the many reasons why some people cannot absorb vitamin B12 properly. For example, up to 50% of people who have bypass gastric surgery to help them lose weight can become deficient within a year of surgery.
Supplementing with Vitamin B12
Fortunately, many of these people can still absorb vitamin B12 from supplements. This is why fortified foods and supplements are on the rise in supermarkets and health food stores everywhere. In their study, the Australian researchers reported that multivitamin use was associated with serum B12 levels significantly higher than non-multivitamin users.
If you donít want to add another pill to the line-up of morning pills, vitamin B12 injections have proven a useful and effective alternative for preventing deficiency. The injections usually only need to be administered once every three months, and are relatively cheap and easy to access; though they do leave you with a sore arm for a day or two.
Checking for Vitamin B12 Deficiency
While B12 deficiency can be relatively common, it does not affect everyone. Like most people I'm sure you don't want to take a pill, let alone an injection, if you don't have to. Interestingly vitamin B12 deficiency usually takes years to develop, mainly because it is recycled very efficiently in your body, and your liver keeps such a good store of it. This means that you can catch a decline in levels early and do not need to wait for symptoms to appear to tell you something's wrong. Arguably, this is the important take-home message from the study: it's important to test regularly for vitamin B12 deficiency. While it is particularly important to do this as a person gets older, there's some evidence that one in five of the general public can be deficient as well.
The easiest way to check for vitamin B12 deficiency is to test blood levels of it by doing a serum B12 test. Sometimes however, the result can come back as a false negative i.e. it says you have enough, but you may still be experiencing symptoms of vitamin B12 deficiency. In these cases a second blood test can be performed to check MMA (methylmalonic acid) levels and homocysteine levels. Both MMA and homocysteine will rise in the presence of a B12 deficiency.
Mirkazemi C, Peterson GM, Tenni PC, Jackson SP. Vitamin B12 deficiency in Australian residential aged care facilities. The Journal of Nutrition, Health and Aging. 2012;16(3):277-80.
Andres E, Loukili NH, Noel E, Kaltenbach G, Ben Abdelgheni M, Perrin AE, et al. Vitamin B12 (cobalamin) deficiency in elderly patients. Canadian Medical Association Journal. 2004;171(3):251-9.
Aarts EO, van Wageningen B, Janssen IM, Berends FJ. Prevalence of Anaemia and related Deficiencies in the First Year following Laparoscopic Gastric Bypass for Morbid Obesity. Journal of Obesity. 2012;
Lindenbaum K, Healton EB, Savage DB, Brust JCM, Garret TJ, Podell ER et al. Neuropsychiatric disorders caused by cobalamin deficiency in the absence of anaemia or macrocytosis. New England Journal of Medicine. 1998;318(26):1720-8
Payinda G, Hansen T. Vitamin B12 deficiency manifested as psychosis without anaemia. American Journal of Psychiatry. 2000;157(4):660-1.
Veldt BJ, Zuidgeest DMH, de Beijer-Dominicus JA, Dees A. Loss of vision as a presenting sign of cobalamin deficiency: An eye-opener. European Journal of Internal Medicine. 2006;17(4):292-4
Oh RC, Brown DL. Vitamin B12 deficiency. American Family Physician. 2006;67(5):979-86