Hi, and congratulations on your pregnancy. Babies and pregnant women are so beautiful.
I am a man, so maybe not the most credible advisory on pregnancy and nursing, but I was very involved throughout my wife's pregnancy, birth, nursing, etc. The longer you can breast-feed, the better, for both you and your child. My wife nursed our son for 13 months (she deserves a medal!), and he is smart, healthy, and in the top percentiles for height and weight. It is an immeasurable gift, in my most humble opinion.
I was thinking that 5,000 IU of Vit. D3 was better than 2,000, when I saw jimmylegs suggest 4,000. Either, or. Cold water fish oils are good too (cod, herring, anchovy, salmon...).
Keep your folic acid up - through leafy greens - collards, kale, chard, etc., which will also give your baby a good birth level of Vit. K. Ideally, you have been doing all that since before conception.
For goodness sake, don't let them give your baby any injections of anything before at least 2 years old. There is incredible pressure to give Vit. K shots, Hep C vaccine (for weeping sake!), and goodness alone knows what else - in the delivery room!. Do not let them put anything into your baby - unless, of course, it is an emergency. Try to let the umbilical cord pump all of its blood into the baby before cutting it too, unless of course, you are keeping cord blood for future treatments (we did, but I'm not sold on it), or there is a contraindication to your, or the baby's health.
I hope that my male voice is not unwelcome, and all the best to you.
My name is not really Johnson. MSed up since 1993