For me, it doesn't matter what time I take them, but I aboslutely MUST take them with food! I guess my stomach is extremely sensitive. The best bet would be to run it by your Dr. When I was pregnant I had to take an iron supplement along with my Prenatal Vitamins. My Dr. advised me to take one in the morning and the other at night. This is because the Iron mixed with the Prenatal could cause painful costipation if taken together. Therefore, advice from a Dr. might be the best bet!