A member asked:
I've recently had 1000mg of b12 (apparently correct dose for my weight). could this have an effect on my menstrual cycle? my last period was june 3. i have taken a pregnancy test that has come back negative.
3 doctor answers • 5 doctors weighed in

Dr. Howard Cohenanswered
Cardiac Electrophysiology 62 years experience
Probably not: Several of the B vitamins including B12 are necessary for a normal menstrual cycle, but taking B12 is unlikely to be the cause of missing a menstrual cycle completely. I assume there is a specific reason for taking the B12, because a normal diet would supply enough unless you have a condition in which your body cannot absorb the B12 or your body is unable to effectively use the B12 it gets.
607 viewsReviewed >2 years ago

A Verified Doctoranswered
A US doctor answeredLearn more
No : B 12 injections do not affect the menstrual cycle . Please repeat the pregnancy test and see your GP .
505 viewsReviewed >2 years ago

Dr. Jovita Anyanwuanswered
Internal Medicine 31 years experience
Vitamin B12: injection will not affect your periods. However if you are exercising and losing weight the the weight loss and intense exercise can cause you not to have periods
504 viewsReviewed >2 years ago
Last updated Nov 27, 2017
People also asked
Connect with a U.S. board-certified doctor by text or video anytime, anywhere.
24/7 visits - just $39!
50% off with $15/month membership
Disclaimer:
Content on HealthTap (including answers) should not be used for medical advice, diagnosis, or treatment, and interactions on HealthTap do not create a doctor-patient relationship. Never disregard or delay professional medical advice in person because of anything on HealthTap. Call your doctor or 911 if you think you may have a medical emergency.