In the multivitamin prenatal of rainbow light with 10 mg thiamin mononitrate, it is high over the recommended 1,5mg/day of rads. can i take prenatal o?

It is fine: Thiamine is a B vitamin and it will not harm you at all to take a slightly higher than normal dose. B vitamins are water soluble and any extra that you have gets flushed out in the urine. If you are taking it as a prenatal vitamin make sure it has folate or folic acid in it. Folate is important for preventing neural tube defects, a type of birth defect.