vitamin question..

I have IBS which has caused me to have a major deficiency in B12 , D3 and folic acid , I have been taking (before pregnancy) b12 - 50mcg , D3 - 5000IU and Folic acid - 4 mg twice a day, on top of it all i am anemic. I was told it was safe to still take them as my prenatal vitamins still aren't enough in those areas. I'm pretty sure if doc says it is ok , then it is ok but just for my own piece of mind has anyone else been in the same situation? it helps a lot with my IBS symptoms and of course with all around health issues caused by IBS and vitamin deficiencies. TIA 💛