Hello Thanks for the query. Vitamin B-12 is a nutrient that keeps the body s blood cells and nervous system healthy. A deficiency in B-12 can lead to health problems such as depression and fatigue. These are also common problems that many women experience during their menstrual cycle. Women lose 50-60ml of blood each menstrual cycle, so it is important to replace all the nutrients lost during menstruation. Vitamin B-12 plays an important role in the formation of red blood cells, so B-12 is especially important during this time. A deficiency in B-12 can lead to a type of anemia called pernicious anemia which causes extreme fatigue. Vit B12 is less likely to cause spotting inbetwwen the menstrual cycle. I recommend you to get a colposcopy done. followed by colposcopic directed biopsy. Hope this helps. Regards, Dr Nilofer