We don’t judge whether you have enough vitamin D just based on what you eat anymore.  In part that's because the sources of the vitamin are both sun exposure and diet.  They aren't the same every day and they really aren't the critical issue.

Breastmilk contains protein, fat, carbohydrates, calcium, iron, vitamins, and the other minerals. Yet surprisingly, the average mom’s diet has very little impact on her breastmilk or the baby (except for vitamins).The baby generally will not suffer if his mother doesn't have enough protein or iron, for example. He will receive all he needs unless the mother is experiencing a critical shortage.