Riboflavin is essential for keeping your cells stable and to produce energy. It is used as a headache preventive at the 400mg dose per day. In the literature, there are a few trials to support it. In fact, there are only two.
In one trial by Schoenen and colleagues, 55 people were divided into two groups. The group that took Vitamin B-2 
What scientists would like to see are more trials, of course, with larger study groups. However, funding for such trials is very difficult to come by.
Riboflavin should be taken in the morning. Since it gives you energy, that energy would be of best use to you in the daytime. If you take it in the afternoon, you might have problems sleeping. It does also turn your urine fluorescent yellow. It is very well tolerated but rarely, someone may experience stomach upset or diarrhea.
Although it is a vitamin, using it for a headache preventive in pregnancy cannot currently be recommended since the dose effect on the fetus is unproven.
I have been reading about all the supplements you have written about for Migraine Headaches, but can you mix all of them together such as Vit.D, CQ10, Riboflavin, Magnesium? I have been taking Vit D drops and started CQ 10. I dont know how much of each is enough. I also take Prescription medications. Please let me know. I hope all is well with you and your Family, and you are enjoying the Summer.
Mary
Hi Mary, you can mix all of them. Take the Vit D no matter what and add one of the others so that if you are sensitive, you’ll know. But you certainly can take them all and with prescription meds too.