Vitamin B12 injections for the elderly
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* Francesco Anello

In their article on the use of vitamin B12 injections for elderly patients by primary care practitioners in Ontario, Carl van Walraven and David Naylor acknowledge that a major problem with their study is that overutilization is identified but underutilization is not.1 Patients with cobalamin deficiency, but with normal serum vitamin B12 levels according to current definitions, may present with neuropsychiatric symptoms ranging from innocuous paresthesias and fatigue to dementia and psychosis.[2, 3] Practitioners cognizant of the serious morbidity possible with cobalamin deficiency might opt to risk overutilizing this safe, inexpensive therapy: serum vitamin B12 determinations cost the system approximately $20 and vitamin B12 therapy is relatively inexpensive. Although functional biochemical testing of methylmalonic acid and homocysteine levels prior to commencing therapy would reduce overutilization (and underutilization), these tests, which cost $160 in total, are currently not covered by the Ontario Health Insurance Plan. This is an unacceptable financial burden for the elderly population.

Metabolic evidence from the Framingham study showed that cobalamin deficiency is present in 1 in 8 or 1 in 5 elderly people.4 Yao and colleagues suggested that serum cobalamin screening be done for every person aged 65 and older and that the normal range be increased to 250-300 pg/mL.5 Screening for cobalamin deficiency at our south-western Ontario community health clinic yielded a 20% prevalence in the elderly.

Dementia and impaired cognitive functioning may result from vitamin B12 deficiency, although most of the evidence is from observational studies.[4–6] The costs of misdiagnosing a potentially reversible dementia resulting from cobalamin deficiency may justify erring on the side of overutilization until more studies are done on the utility of vitamin B12 treatment. Fewer interventions in primary care are as simple, safe and satisfying to both practitioner and patient as the detection and appropriate treatment of symptomatic cobalamin deficiency.

## References

1.  1. van Walraven CG, Naylor CD. Use of vitamin B12 injections among elderly patients by primary care practitioners in Ontario. CMAJ 1999;161(2):146-9.
    
    [Abstract/FREE Full Text](http://www.cmaj.ca/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6NDoiY21haiI7czo1OiJyZXNpZCI7czo5OiIxNjEvMi8xNDYiO3M6NDoiYXRvbSI7czoyMToiL2NtYWovMTYyLzkvMTI3NC5hdG9tIjt9czo4OiJmcmFnbWVudCI7czowOiIiO30=) 

2.  2. Pennypacker L, Allen R, Kelly J, Matthews LM, Grigsby J, Kaye K, et al. High prevalence of cobalamin deficiency in elderly outpatients. J Am Geriatr Soc 1992;40:1197-204.
    
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    [Web of Science](http://www.cmaj.ca/lookup/external-ref?access_num=A1992KA80900001&link_type=ISI) 

3.  3. Healton EB, Savage DG, Brust CM, Garrett TJ, Lindenbaum J. Neurologic aspects of cobalamin deficiency. *Medicine (Baltimore)* 1991;70:229-45.
    
    

4.  4. Lindenbaum J, Rosenberg I, Wilson P, Stabler S, Allen R. Prevalence of cobalamin deficiency in the Framingham elderly population. Am J Clin Nutr 1994;60:2-11.
    
    [Abstract/FREE Full Text](http://www.cmaj.ca/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6NDoiYWpjbiI7czo1OiJyZXNpZCI7czo2OiI2MC8xLzIiO3M6NDoiYXRvbSI7czoyMToiL2NtYWovMTYyLzkvMTI3NC5hdG9tIjt9czo4OiJmcmFnbWVudCI7czowOiIiO30=) 

5.  5. Yao Y, Yao SL, Yao SS, Yao G, Lou W. Prevalence of vitamin B12 deficiency among geriatric outpatients. J Fam Pract 1992;35:524-8.
    
    [PubMed](http://www.cmaj.ca/lookup/external-ref?access_num=1331288&link_type=MED&atom=%2Fcmaj%2F162%2F9%2F1274.atom) 
    
    [Web of Science](http://www.cmaj.ca/lookup/external-ref?access_num=A1992JY16800012&link_type=ISI) 

6.  6. Bell IR, Edman JS, Marby DW, Satlin A, Dreier T, Liptzin B, et al. Vitamin B12 and folate status in acute geropsychiatric patients: affective and cognitive characteristics of a vitamin nondeficient population. Biol Psychiatry 1990;27:125-37.
    
    [PubMed](http://www.cmaj.ca/lookup/external-ref?access_num=2294976&link_type=MED&atom=%2Fcmaj%2F162%2F9%2F1274.atom) 
    
    [Web of Science](http://www.cmaj.ca/lookup/external-ref?access_num=A1990CH93800002&link_type=ISI)