YES!! I found this. I am 7+3 and I didn't want to take a multi-vitamin because I wanted to take Floravital liquid iron and didn't want to overdose. Instead I had separate Folic Acid, Calcium with 5ug of Vit D, plus Vit D 20ug. (All from Veganicity via Amazon).
I was VERY ill and was off work for 2 days; so I stopped taking the Calcium and Vit D and nausea stopped within 24 hours.
I discussed with my midwife; she wasn't overly happy about me not taking Vit D but I said I would start again in my 2nd trimester.
I wonder if it's too much Vit D that's made us sick?
I should also say, my niece had exactly the same with her pregnancy (gave birth to her second on Sunday 28th) when taking multi-vitamins; she found they made her really sick so just took singular folic acid.