You may be very conscious of your health and well-being at this time but be reassured that even if you've felt unwell during this first trimester, your baby will have been taking what she needs from you: you have internal reserves of various minerals and substances, such as iron, and will still be absorbing some nutrients from what you eat. However, if you're concerned about the amount of vitamins and minerals you're consuming through your diet, for the sake of your own health you could take a prenatal vitamin supplement. Remember, you should still be taking folic acid supplements and eating folate-rich foods (see Take folic acid). There is no cause for concern if you do not put on any weight in the first trimester, or even if you lose a bit of weight. The majority of weight gain takes place in the second and third trimesters (see How much weight will you gain?).
If you're vomiting a lot and struggling to keep food down (see Fit-not sick), don't hesitate to see your ob/gyn.