Background: Low folate levels are associated with megaloblastic anemia, neural tube defects, and an increased risk of cancer. Data are scarce regarding the sex aspect of this deficiency.

Objectives: To assess sex differences in folate levels in a large cohort of patients and to investigate the effect of low folate levels on homocysteine concentrations.

Methods: Data were collected from medical records of patients examined at a screening center in Israel between 2000 and 2014. Cross sectional analysis was conducted on 9214 males and 4336 females.

Results: The average age was 48.4 ± 9.5 years for males and 47.6 ± 9.4 years for females. Average folate levels were 19.2 ± 8.6 and 22.4 ±10.3 nmol/L in males and females, respectively (P < 0.001). The prevalence of folate levels below 12.2 nmol/L was 19.5% in males compared to 11.6% in females (P < 0.001). In patients with low folate levels and normal B12 levels, homocysteine levels above 15 μmol/L were found in 32.4% of males and 11.4% of females (P < 0.001). Males had a significantly higher odds ratio (OR) of having folate levels below 12.2 nmol/L: OR 1.84 (95% confidence interval [95%CI] 1.66–2.05) in a non-adjusted model, and OR 2.02 (95%CI 1.82–2.27) adjusted for age, smoking status, body mass index, kidney function, albumin, and triglycerides levels.

Conclusions: Folate levels are lower in males compared to females, which may contribute to the higher homocysteine levels found in males and thus to their increased risk of developing atherosclerosis and coronary artery disease.