Ignoring the Impact of Fermentation Could Result in Substantial Misestimation of Folate and Cobalamin Adequacy: A...

B-vitamin content of plant-based foods can be deeply modified by fermentation, particularly the active cobalamin form, which is often considered to be zero in food composition databases. We simulated the consequences of including or excluding the impact of fermentation in estimating folate and cobalamin adequacy using secondary data obtained from a survey of 323 women in Ethiopia plus the vitamin content of injera (fermented flat bread) reported in the literature. As folate content can change during fermentation, the prevalence of inadequacy in scenarios that include the effect of fermentation was higher (90%) or lower (67%) than in the original data. Our simulation based on data obtained using cobalamin-producing microorganisms lowered the prevalence of inadequacy to 54%. Ignoring the impact of fermentation may result in substantial misestimation of folate and cobalamin adequacy in Ethiopia, and it should be evaluated in other contexts in which fermented foods are consumed as staple foods.