Folic acid deficiency. Light micrograph of cervical smear showing cells with folic acid deficiency. The pink-stained epithelial cells seen here are abnormally enlarged, with disturbed large nuclei. Nuclear replication is seen in several cells (at upper right and upper left) with condensed chromatin apparent within each nucleus. Folic acid is a vitamin essential in the production of red blood cells by the bone marrow. Deficiency is caused by a poor diet or serious illness. Papanicolaou stain. Magnification: x400 at 35mm size.