Is she trying to overdose me?!

Sometimes I think that my midwife does not know what she’s talking about. I live in the UK and I am pregnant. I am currently taking prenatal vitamins called “pregna care”. Pregna care has all needed vitamins such as 400mg folic acid and vitamin D...now guess what? My midwife said that I need 500mg folic acid and more vitamin D because I am considered overweight so she prescribed another tablet of folic acid and vitamin d and have asked me to take the three of them together... isn’t that too much folic acid and vitamin D? So that is 500mg + 400mg folic acid when she’s saying I only need 500mg... what?! It’s all confusing...