Due to low vit d, i was prescribed vit d. can high dose of vitamin d cause a period to be missed? past 4 month cycles were 36,32,37,36. is irregular?

It is more likely: that untreated low vitamin D levels might affect the menstrual cycle. That said, in my experience, the menstrual cycle is a very sensitive barometer of changes that are going on in the body and I wouldn't be comfortable saying that excess vitamin D couldn't affect the menstrual cycle. Whether missed or irregular? Doesn't really matter...if irregular enough, say 45 days+, it seems missed.