Supplementary Material for: Consumption Pattern of Tea is associated with Serum Ferritin Levels of Women of Childbearing Age in Nandi County, Kenya: A Cross-sectional Study

Introduction: Tea consumption with meals affects iron absorption increasing the risk of iron deficiency. Our study investigated the association between tea consumption patterns and serum ferritin levels among women of childbearing age (WCA) in Nandi County, Kenya.
Methods: We conducted a cross-sectional analytical study among 160 WCA selected using a systematic random sampling technique from Kapsabet Ward. Information on tea consumption practices was gathered using a researcher-administered questionnaire, and serum ferritin and C-reactive protein were measured. We assessed associations between tea consumption and iron status of respondents by multivariable regression analysis, adjusting for potential confounders, including parasitic infections and recent severe blood losses.
Results: The prevalence of anaemia and iron deficiency among the study participants were 86.2% and 45%, respectively. Majority (90.6%) of the respondents consumed tea or coffee, with an infusion time of more than 5 minutes (60.0%) and a moderate tea strength (64.1%), within 1-hr before or after meals. Iron deficiency was associated the number of teacups consumed (adjusted odds ratio = 7.282, 95% CI = 3.580-14.812).
Conclusion: High tea consumption is positively associated with iron deficiency among WCA. Lower tea infusion strength, shorter tea infusion duration, and a lower number of teacups overall consumed, as well as consuming tea one hour before or after meals instead of with meals may be recommended for better outcomes in iron status among WCA.