Blood Concentrations of Homocysteine and Methylmalonic Acid among Demented and Non-Demented Swedish Elderly with and without Home Care Services and Vitamin B12 Prescriptions

Abstract

Background and Aims: Total plasma homocysteine (tHcy) has been suggested as a risk factor of dementia. Our aim was to investigate potential differences in tHcy status in relation to the prescription of vitamin B₁₂ and dementia diagnosis. We examined whether vitamin B₁₂ prescriptions, a family history of dementia, or the need for home care service might be associated with tHcy values. Methods: A cross-sectional monocenter study comprising 926 consecutive subjects attending our Memory Care Unit was conducted. Results: Demented subjects being prescribed vitamin B₁₂ had higher serum vitamin B₁₂ (p = 0.025) but also higher tHcy (p < 0.001) and serum methylmalonate (p = 0.032), and lower serum folate (p < 0.001) than those who did not receive vitamin B₁₂ prescriptions. tHcy levels were significantly higher in non-demented subjects receiving home care service (p = 0.007). This group also had lower serum albumin (dementia: p < 0.001; non-dementia: p = 0.004). There was no difference in renal function (estimated glomerular filtration rate) in demented or non-demented subjects with or without vitamin B₁₂ prescriptions (dementia with/without vitamin B₁₂ prescription: p = 0.561; non-dementia with/without vitamin B₁₂ prescription: p = 0.710). Conclusion: Despite vitamin B₁₂ prescriptions, demented subjects had higher tHcy and methylmalonate values. The elevated metabolite values could not be explained by differences in renal function. Thus, elderly subjects on vitamin B₁₂ prescription appear to have unmet nutritional needs.