Age and Ageing Advance Access originally published online on January 17, 2007
Age and Ageing 2007 36(2):231-232; doi:10.1093/ageing/afl158
Low serum vitamin B12 in older people: the role of alcohol and thyroid status
Hin et al. highlight an important point to connect the clinical relevance of biochemical evidence of vitamin B12 deficiency in the absence of anaemia in older people [1]. Although the authors have looked into the demographics of the total cohort of 1000 patients in detail, there is surprisingly no mention about two very important and commonly encountered factors in clinical practice that could account for low B12 levels and macrocytosis respectively—alcohol intake and thyroid status.Elevation of mean cell volume (MCV) is a common clinical problem, but the aetiologic spectrum and optimal diagnostic evaluation of macrocytosis are not well defined, and drugs and alcohol are the most common causes of macrocytosis [2], and indeed alcohol abuse plays a key secondary role in macrocytosis. This has significant implications given the evidence from a large population-based study of older adults examining the mortality risks of alcohol use and comorbidity, where at-risk drinking was associated with greater mortality rates [3].
Likewise, the results have also shown that ‘medications producing hypochlorhydria, such as H2-antagonists and proton pump inhibitors, were in common use but were unrelated to low vitamin B12 concentrations’ [1]. Of late, Centanni et al. have shown that in patients with impaired acid secretion (e.g. omeprazole therapy or Helicobacter pylori infection), the requirement for an increased dose of thyroxine is warranted, demonstrating that normal gastric acid secretion is necessary for effective absorption of oral thyroxine [4]. Hence the data on thyroid status as well as those taking thyroxine among the cohort studied would have been crucial and relevant to the results of the study. Non-megaloblastic macrocytosis is well recognised to occur with alcoholism and hypothyroidism. [5]
This has particular inference given the significantly higher mean corpuscular volume (P = 0.0025), with low B12 concentrations, despite the fact that there were no differences in haemoglobin concentrations [1], and merits further evaluation.
AIV works in oral surgery and dentistry and is involved with the care of elderly patients with oral pathologies associated with vitamin B deficiency and GIV is a specialist registrar in endocrinology and general (internal) medicine and has encountered elderly patients with hypothyroidism and macrocytosis in daily routine clinical practice.
1 Senior House Officer in Oral and Maxillofacial Surgery, Northampton General Hospital, Northampton NN1 5BD, UK
2 Diabetes and Endocrinology, University Hospital of North Staffordshire, Stoke-on-Trent ST4 6QG, UK
* To whom correspondence should be addressed Tel: (+44) 1908 696131 Fax: (+44) 1908 696130 Email: aiype{at}yahoo.com
References
- Hin H, Clarke R, Sherliker P, et al. (2006) Clinical relevance of low serum vitamin B12 concentrations in older people: the Banbury B12 study. Age Ageing 35 416–22.
[Abstract/Free Full Text] - Savage DG, Ogundipe A, Allen RH, Stabler SP, Lindenbaum J. (2000) Etiology and diagnostic evaluation of macrocytosis. Am J Med Sci 319 343–52.[CrossRef][Web of Science][Medline]
- Moore AA, Giuli L, Gould R, et al. (2006) Alcohol use, comorbidity, and mortality. J Am Geriatr Soc 54 757–62.[CrossRef][Web of Science][Medline]
- Centanni M, Gargano L, Canettieri G, et al. (2006) Thyroxine in goiter, Helicobacter pylori infection, and chronic gastritis. N Engl J Med 354 1787–95.
[Abstract/Free Full Text] - Davenport J. (1996) Macrocytic anemia. Am Fam Physician 53 155–62.[Web of Science][Medline]
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