Objective: To assess the relationship between serum folate level and the risk of fatal coronary heart disease (CHD) among men and women.
Design: Retrospective cohort study with serum folate levels measured from September 1970 to December 1972, with follow-up through 1985.
Setting: Participants in the Nutrition Canada Survey.
Participants: A total of 5056 Canadian men and women aged 35 to 79 years with no history of self-reported CHD.
Main outcome measure: Fifteen-year CHD mortality.
Results: A total of 165 CHD deaths were observed. We found a statistically significant association between serum folate level and risk of fatal CHD, with rate ratios for individuals in the lowest serum folate level category (<6.8 nmol/L [3 ng/mL]) compared with the highest category (>13.6 nmol/L [6 ng/mL]) of 1.69 (95% confidence interval, 1.10-2.61).
Conclusions: These data indicate that low serum folate levels are associated with an increased risk of fatal CHD.