Vitamin B6 is very beneficial to fertility and PMS.
It helps lengthen the luteal phase and also helps with depression associated with PMS.
A luteal phase defect is one of the reasons for infertility and is one of the most easily treated. A luteal phase defect is when the luteal phase (the time from ovulation to menstruation) is less than 10 days. Ideally, it would be best if the luteal phase was 11-16 days. A luteal phase that is too short cannot maintain a pregnancy, usually resulting in miscarriage if measures aren't taken to lengthen the luteal phase. You can detect a luteal phase defect by charting your basal body temperatures. This may take a month or two to catch on and figure out, but it is worthwhile in determining if there is indeed a luteal phase problem. Once you determine this, then you can begin seeking help. And if you detect a luteal phase defect, one way of lengthening the luteal phase is with progesterone supplements and another way is with vitamin B6.
It is recommended to take 100-200 mg of vitamin B6 a day to help with luteal phase defects. Perhaps it would be smart to start out with smaller doses first to see if it would work and increase it if it doesn't. Obviously always check with your practitioner or doctor before taking megadoses of any vitamin. Vitamin B6 helps to normalize hormone levels thus normalizing the luteal phase.
Vitamin B6 occurs naturally in yeast, whole grains, legumes, liver, eggs, cereal, meat and fish.