Imbalances in maternal one-carbon nutrients (vitamin B12, folate) have been shown to be associated with higher offspring cardiometabolic risk markers in India.We examined the hypothesis that low plasma vitamin B12 (B12), and high folate and homocysteine concentrations in the mother are associated with higher hypothalamic-pituitary-adrenal axis (cortisol) and cardiovascular responses during the Trier Social Stress Test for Children (TSST-C) in an Indian birth cohort.Adolescents (n=264; mean age: 13.6 y), whose mothers' plasma B12, folate and total homocysteine concentrations had been measured during pregnancy, completed 5-minutes each of public speaking and mental arithmetic tasks in front of two unfamiliar 'judges' (TSST-C). Baseline and post-stress salivary cortisol concentrations were measured. Heart rate, blood pressure, stroke volume, cardiac output, and total peripheral resistance were measured continuously at baseline, during the TSST-C, and for 10-minutes after the TSST-C using a finger cuff; beat-to-beat values were averaged for these periods respectively. Results: Maternal low B12 status (plasma B12<150 pmol/L) was associated with greater cortisol responses to stress in the offspring (p<0.001). Higher homocysteine concentrations were associated with greater offspring heart rate response (p<0.001). After adjustment for multiple comparisons, there were non-significant associations between higher maternal folate concentrations and offspring total peripheral resistance response (p=0.01).Our findings suggest that maternal one-carbon nutritional status may have long-term programming implications for offspring neuro-endocrine stress responses.