Folate and vitamin B12 levels in abnormal pap smears: a case control study

This study aimed to explore the risk of abnormal cervical cytology in relation to serum folate and vitamin B12 levels, and demographic characteristics.

A case-control study was carried out among women attending the gynecology clinic for cervical cytology screening. At the follow-up clinic visit, fasting blood samples were collected from 103 cases with abnormal cervical cytology of the cervix and 175 controls with cytological normal smears and serum folate and vitamin B12 levels were measured. Data from cases and controls were compared. Logistic regression analysis was used to estimate the relative odds of abnormal cytology with increasing vitamin B12 levels.

There were no significant differences between cases and controls in demographic characteristics and mean folate levels (p > 0.05). The mean vitamin B12 level of cases was significantly lower than that of controls (p < 0.001). Dichotomized logistic regression analyses of vitamin B12 levels were significantly different (p < 0.001). The predicted percentages at a cut-off value of 0.5 were as follows: sensitivity 70.0%, specificity 74.6%, positive predictive value 71.8% and negative predictive value 72.6%. The logistic regression analysis of the 1st and the 4th quartiles of vitamin B12 levels showed a significant difference p < 0.001, OR: 1.525 (CI, 1.175-1.875).

The results of this study suggest that lower vitamin B12 levels are associated with abnormal cervical cytology. It is recommended that women should consume not only folate-rich foods such as fruits and vegetables but also vitamin B12-rich foods such as meat, fish, milk products and eggs in a balanced way.