Objective: An elevated homocysteine level in the blood has been identified as an independent risk factor for vascular disease, including coronary atherosclerosis and venoembolic disease. A deficiency of vitamins B ( 6 ), B ( 12 ), or folate in the blood can cause increased blood levels of homocysteine. We set out to determine whether there was a relationship between blood levels of folate and B ( 12 ) and the subsequent development of cardiovascular disease and mortality in old old ambulatory men and women.
Design: Four hundred forty subjects (mean age, 79 years; 64% female) were followed in the Bronx Longitudinal Aging Study, a prospective study of 10 years duration, designed to assess risk factors for cardiovascular and cerebrovascular diseases and dementia in an ambulatory old old cohort.
Methods: Serum levels of vitamin B ( 12 ) and folate were measured and related to the incidence of total all-cause mortality, stroke, myocardial infarction, coronary heart disease, and cardiovascular disease.
Results: No statistical gender- or age-related differences were found in the mean levels of folate or B ( 12 ). The concentration of folate in the blood was not related to the incidence of mortality, myocardial infarction, stroke, or overall cardiovascular disease. However, by logistical regression and Cox proportional-hazards regression analyses, there was an increased incidence of mortality and coronary heart disease in those subjects having increased vitamin B ( 12 ) levels in the blood. Each 100-pg increase in B ( 12 ) was associated with a 10% increase in mortality and coronary heart disease incidence.
Conclusion: These results suggest that in elderly subjects, vitamin B ( 12 ) supplementation should not be routinely provided unless there are clear indications for doing so (a deficiency state), and then only to replace enough B ( 12 ) to correct the deficiency. A suggested treatment paradigm is provided for managing vitamin deficiency states and hyperhomocysteinemia in elderly subjects.