Her advice: Keep taking a prenatal multivitamin with iron for the length of time you’re breastfeeding, or if you’re not breastfeeding, for as long as you have post-delivery bleeding. Plus, eat iron-rich foods, such as red meat, fortified whole-grain products, beans, lentils and leafy greens. You should feel better within a couple of weeks of boosting your iron intake, but more severe deficiencies (indicated by shortness of breath, pale skin, dizziness, a swollen tongue, cold hands and feet or cravings to eat non-food items like ice cubes) may take longer to sort out.