Masked vitamin B12 and folate deficiency in the elderly

1. A high incidence of vitamin B12 or folate deficiency, or both, may be found in the elderly, particularly those in hospital. This report concerns fifty cases detected in an inner-city-area geriatric unit during the course of routine clinical investigation. The majority had none of the classical haematological signs of vitamin B12 or folate deficiency, and all the patients reported had a mean corpuscular volume (MCV) of less than 100 fl. 2. There was a significant negative correlation between the MCV and the erythrocyte folate (P less than 0.01), supporting earlier published work using a low serum folate as an index of folate deficiency. 3. There was no correlation between the MCV and the serum vitamin B12. Published work differs on this point. 4. Serum iron, total Fe-binding capacity and percentage Fe saturation results were available in forty patients in this series. There was a significant positive correlation between the serum Fe and the MCV (P less than 0.01) and 34% of patients had haematological evidence of Fe deficiency. In the majority, however, there was no evidence that associated Fe deficiency had masked the haematological signs of vitamin B12 or folate deficiency. 5. More attention should be paid to the problem of 'masked' vitamin B12 and folate deficiency in the elderly. There is a case for routine screening of the elderly for vitamin B12 and folate deficiency irrespective of the MCV.