Task: Answer Verification
Input (English): Question: Is ( 13 ) C enrichment of the CO2 in breast milk and in the breath rapidly modified by changes in the ( 13 ) C content of the diet?
Answer: Subjects eating a C4 diet have a higher δ(13)CPDBV value in the breath and breast milk fractions, which diminish rapidly on a C3 diet. Further studies focusing on individual nutrients are warranted.
Output (English): yes