Efficacy of tea as an ideal vehicle for therapeutic vitamin replacement in women with low folate and vitamin B ₁₂ status in Assam: a placebo-controlled interventional clinical trial

Background Most Indian women have a low folate and vitamin B 12 status that can progress to clinical deficiency and contributes to over 100 000 births annually with neural tube defects (NTDs). A common, widely accepted, Indian food vehicle for fortification with folate and vitamin B 12 has long remained elusive. Earlier, we employed folate and vitamin B 12 -fortified teabags to brew a daily cup of black tea and documented improvement in serum folate and vitamin B 12 concentrations among women from Maharashtra state within 60 days. Because most Indian households prefer hot-brewed (‘loose’) black tea prepared by the ‘crush, tear, curl’ (CTC) method in large commercial tea factories, we tested the feasibility of directly fortifying CTC tea with folate and vitamin B 12 and assessed its efficacy in improving the folate and vitamin B 12 status among women from Assam state within 90 days. Methods Two groups of women studying nursing (n=30) or pharmacy (n=30) at Assam Medical College and Hospital consumed a daily cup of hot tea prepared from 2 g of either unfortified CTC tea (control group) or vitamin-fortified CTC tea containing 1 mg folate and 1 mg vitamin B 12 (experimental group) for 90 days. We then compared their pre-interventional versus post-interventional changes in serum folate and vitamin B 12 status, iron status and haemoglobin concentration. Results At baseline, 89% of all women had low folate status (serum folate ≤5 ng/mL) and 72% had low vitamin B 12 status (serum vitamin B 12 ≤300 pg/mL). After 90 days daily consumption of unfortified CTC tea, the control group had clinically insignificant mean increases in serum folate of 1.3 ng/mL and serum vitamin B 12 of 1 pg/mL. By contrast, the experimental group consuming vitamin-fortified CTC tea exhibited a mean rise in serum folate of 5.3 ng/mL (95% CI 3.9 to 6.8; p<0.001) and serum vitamin B 12 of 194.6 pg/mL (95% CI 154.7 to 234.5; p<0.001). Moreover, 28/30 women receiving vitamin-fortified CTC tea had a post-interventional rise in mean serum folate of 9.2±3.6 (SD) ng/mL, and 25/30 women normalised their serum vitamin B 12 ≥300 pg/mL. However, only a minority achieved the higher serum folate concentration required to reduce their risk of NTDs. Despite borderline low normal iron status in most women, there was no adverse impact of CTC tea—consumed ~2 hours between meals—on either per cent-transferrin saturation or haemoglobin concentration. Conclusions Consumption of a daily cup of hot brewed folate and vitamin B 12 -fortified CTC tea is feasible, efficacious, and safe to clinically normalise the folate and vitamin B 12 status of Indian women within 90 days in Assam. Therefore, CTC tea is an ideal and eminently scalable food vehicle for fortification with these vitamins. The next challenge is to determine the optimum duration and/or dose of vitamins required to fortify CTC tea sufficient to lower the risk of NTDs among women across India. Trial registration number CTRI/2022/10/046289.