Vitamin C to Decrease Effects of Smoking in Pregnancy on Infant Lung Function

Inclusion Criteria: At randomization: * Singleton gestation * ≥ 15 years old * Gestational age between 13 and 22 weeks * Receiving prenatal care * Current smoker * English speaking Exclusion Criteria: * Gestational age ≥ 23 and 0/7 weeks * Multiple gestation * Major fetal congenital anomalies * Current use of illicit drugs * Current alcohol abuse * Use of vitamin C (≥ 500 mg/day)\>3 days per week since last menstrual period * Refusal to abstain from vitamin or supplements containing significant vitamin C other than those provided through or approved by study staff * History of kidney stone in patient * Insulin dependent diabetes * Complex maternal medical conditions * Participation in other conflicting research projects * Unable to demonstrate stable method of communication * Pregnancy by in-vitro fertilization * Plan to terminate pregnancy * Failure of medication compliance trial * Failure to return in designated period during placebo run-in * Body mass index \> 50 at screening