Here is a little article I read over that I found interesting:
“One reason that women can experience infertility is called a “short luteal phase” or a “luteal phase defect” (LPD). In real life, what is happening is that the interval from the time you ovulate until you have your period is too short. A fertilized egg needs a certain amount of time to safely implant in the uterine lining- if your hormones are telling the uterus to menstruate too soon, the pregnancy will not be able to implant firmly and you will get your period even though you may in fact have conceived.
How do you know if you have a luteal phase problem? Many women assume that if they have a short cycle (less than 29 days) they might have LPD. In fact, I have found that it is more common to have a LONGER than usual cycle- often as many as 40 days. But longer or shorter, the only way to know for sure is to use an ovulation predictor kit or chart your temperatures and cervical fluid signs for at least a month. If the interval between the day of ovulation and the first day of your period is less than 12 days, you may have LPD.
Once you know you have LPD, the next question is how to lengthen your luteal phase. Typically, a reproductive endocrinologist will supplement your progesterone level, which often works. However, I have found great success, supported by all the research I have done, with simple supplementation with vitamin B6.
The RDA or DV of B6 is extremely low- only a couple of milligrams. For this reason, most women assume they’re getting plenty with their multiple or prenatal vitamin. However, the dosage typically needed to correct LPD is between 50 mg and 300 mg daily. I would advise starting out with an additional 50 for an entire cycle (start supplementing as soon as you get your period and don’t forget to chart or use OPKs through the cycle to see if the LP changes). If the luteal phase does not change, or does not change enough, increase another 50 or 100 for each additional cycle until correction is seen. I don’t know anyone who has had to take more than 300 mg- most see a radical change under 200.
So why does B6 work? Well, B6 is a very complex vitamin and has many actions in the body, but the most likely explanation is that B6 lowers the amount of prolactin in the system. Prolactin is a hormone that, in excess amounts, interferes with ovulation and the regularity of cycles. The majority of women that I have talked to encountered a LPD after coming off the birth control pill. Birth control pills cause a deficiency in B6, which can make your prolactin levels rise, which can in turn lead to a luteal phase defect. Supplementation with these large doses of B6 corrects the deficiency and the timing of ovulation hopefully goes back to normal.
Is there a concern about too much B6? B6 is not a vitamin prone to overdose- it is water-soluble and the excess will simply be secreted in the urine. Women who are establishing breastfeeding may want to keep their levels lower, since prolactin is also the hormone that controls milk production, but I have taken an extra 50 mg daily with no adverse affect on milk supply. But the average woman who is trying to conceive should have no problem with the short-term supplementation I am talking about here.
My own personal experience has been two episodes of LPD, both after coming off birth control (once the “regular” pill and once the minipill). In each instance my period has been 40 or more days for a period of four or five cycles, but with ovulation occuring only at day 30 or so. The first time I took B6 I only took 50 mg daily and the cycle corrected instantly- I ovulated on day 14 and got a positive pregnancy test on day 28, and a beautiful daughter 9 months later. The second time (after the minipill) I started with 50 milligrams, but began the supplementation on day 10. There was no change in the cycle, which was 42 days. The second cycle I took an extra 100 mg. Sure enough, I ovulated on day 14. I don’t know whether or not I am pregnant, but I believe that even if I am not, my cycle will at least be regulated at 30 days. I plan to continue the supplementation at the current level until I am pregnant.”