My doctor told me that B6 lowers the amount of prolactin in the system. In excessive amounts, prolactin interferes with with ovulation and the regulation of cycles. B-12 is not helpful in lengthening the luteal phase. I was also told that in order for the B6 to be beneficial it needs to be taken with other b vitamins, so I take it in a complex. I took just 65 mg. and my luteal phase went from 7-8 days to 12, then 13, and now 14 days in the 3 months I've taken it. Highly recommended! Forgive me for sounding ignorant, but why is B6 not vegan?