Assessment of zinc Fortification of a Household- Based Water Filtration Device: Zn Absorption Using Stable Isotopes and Efficacy in a Controlled Trial in Beninese School Children.

ABSTRACT

Objectives: Zinc bioavailability from foods is limited due to the presence of absorption inhibitors. Water as a vehicle for zinc could be effective in improving zinc status. LifeStraw®Family (LSF) is a water filtration device that fortifies water with zinc. We assessed the absorption of zinc and the response of plasma zinc (PZn) to long-term consumption of the zinc fortified water. Methods: The LSF filters were placed in rural households in Benin (n=139) to assess compliance and acceptability. Bioavailability was measured in young adults with the urinary monitoring of two stable zinc isotopes. A double blind, randomised, controlled trial (RCT) was carried out in school children aged 5-10y (n=278) from a rural village in Benin. Over 20 weeks, including sparse midpoint sampling, children received either zinc fortified LSF-filtered water (Zn), non-fortified LSFfiltered water (Fltr) or non-fortified non-filtered water (Ctrl). The Zn group received a daily zinc dose of 4.6±2.2 mg. Results: Geometric mean (-SD,+SD) zinc absorption from fortified water was 65.9% (42.2,102.4). At baseline, mean PZn was 69.2±12.6 μg/dl and 35.9% of children were zinc deficient. During the RCT, there was a significant treatment effect on PZn (ANCOVA, p=0.029) final PZn in the Zn group was 4.2 and 1.9 μg/dl higher than the Fltr and the Ctrl group, respectively. Further analysis integrating the sparse midpoint PZn response will allow evaluation of plasma zinc kinetics. Conclusions: The LSF filter delivers water fortified with low doses of highly bioavailable zinc. Long-term consumption of zinc fortified water from the LSF filter improved zinc status in Beninese school children.