High riboflavin tends to increase genome instability when folate status is low. Folate-riboflavin interactive effects on CBMNcyt assay DNA damage biomarkers. It is evident from these results that folate deficiency tends to increase micronuclei, nucleoplasmic bridges and nuclear buds and these effects are further aggravated by high riboflavin in a low folic acid background. For more details refer to Kimura et al 2004 . L, low; H, high; F, folic acid; R, riboflavin.