A population-based intervention study on elevated serum levels of methylmalonic acid and total homocysteine in elderly people:: results after 36 months of follow-up

Objectives. To study the effects of vitamin B12 and folic acid treatment on haematological measures, reported symptoms and clinical findings over a 3-year period. Design. A longitudinal two-cohort study. Setting. A mid-Swedish community. Subjects. A 20% random sample of persons 70 years or older in a defined geographical area were invited to a survey (n = 266). Sixty-nine persons who had serum cobalamin <300 pmol L-1 and serum methylmalonic acid (MMA) ≥0.3 7 pmol L-1 or serum total homocysteine (tHcy) ≥15 unol L-1 and who had no vitamin B12 or folic acid substitution were selected for treatment. Main outcome measures. Serum cobalamin, folate, MMA and tHcy. Presence of gastrointestinal, neurological, psychiatric and some other symptoms, obtained by questionnaire, and Mini Mental State Examination (MMSE) score, vibration sense measurement and findings at a physical examination. Results. After combined vitamin B12-folic acid treatment, all persons normalized their serum tHcy and MMA levels and the effect remained after 3 years. The study design allowed separation of pure vitamin B12 deficiencies from folate and combined deficiencies. There was a tendency towards improvement of vibration sense, especially in the long nerve paths, and improvement of neurological symptoms and oral mucosa findings. No improvement was seen for other symptoms, reflex activity or MMSE score. Conclusions. Vitamin treatment of elderly people in the early phase of the condition may reverse damage that otherwise would become irreversible. If initiated, the treatment should be combined with vitamin B12 and folic acid.