Need advice on thyroid and vitamin D.

My wife is 6th week pregnant. Age 26 height 5’4-5’5 weight 70kg days :11.93 Tablets using : Thyranorm 75mg Follinz Naturogest 300mg Thyroid (TSH) now : 0.48 Thyroid before 50 days was 11.93 so at that doctor advised Thyronorm 75mg is it still required to use 75mg ? She is having only 18.53 vitamin D. Where as normal range is 30-100 as per report . Should she use any vitamin D tablets ? She is continuously feeling hungry. So she is having milk or orange or apple whenever she feels hungry. She generally take little breakfast of 2-3Idlis, She is taking little rice in after noon She eats oats limited quantity in dinner. As she is feeling hungry she is taking orange or apple or milk for every 1-2 hours As soon as she eats she is getting motions in 30mins. Please tell me if it’s common and what we have to do ?